SEMAFO Further Expands Mana's Wona SW Zone Results Include 4.17 g/t Au Over 32 Meters

Kona Infill Drilling Confirms Mineralization Distribution


MONTREAL, QUEBEC--(Marketwire - May 12, 2011) - SEMAFO (TSX:SMF) announced today that recent drilling over the Wona SW zone demonstrates multiple opportunities to further expand underground reserves from those reported in the Mana Underground Feasibility Study. Core drilling values including hole WDC256, which returned 4.17 g/t Au over 32 meters in an area formerly expected to be outside the mineralized zone. Furthermore, results from the in-progress infill drilling program over the Kona open pit area confirmed ore distribution.

The database and block model submitted for the underground Feasibility Study dated October 2010 were closed with diamond drill hole ("DDH") WDC223 and reverse circulation ("RC") hole MRC10-214. At year-end 2010, the updated database (up to WDC256 and MRC10-223) and block model over the Wona-Kona area resulted in the addition of resources to the underground, while new resources and reserves were added to the Kona open pit area. From completion of the underground block model database in October 2010 until early March 2011, 46 diamond drill holes representing 24,500 meters were completed over the Wona deposit and 124 RC drill holes representing 16,300 meters were carried out over the Kona zone. The following table illustrates the Wona zone and parallel structure drill results from the last months of 2010 and until early March 2011. The large volume of drilling explains a lengthier than usual assays turnover time.

Wona

Recent drilling results demonstrated significant potential for new reserves, particularly on the southern-most side of the Wona SW zone, as illustrated on the attached figure. These potential incremental reserves are derived from different sources; some are a result of upgrading former low-grade areas, others are upgrading resources from the inferred to the indicated category and therefore enabling the minimum level of confidence to create reserves and finally, some are an extension of the perimeters. An example of the latter is hole WDC256, where an embayment is created, which returned 4.17 g/t Au over 32 meters. This hole is located in an area where inferred resources had not been established prior to the drilling, as we believed it to be outside the mineralization trend. The extensions will require further lengthening of the proposed development. Additionally, due to their width, the project extensions will most likely be in-ore drifts consistent with Avocat Long Hole Mining. Higher than expected grades in certain areas also identified new upside within the current block model. These areas are crossed by planned drifts and therefore easily converted to reserves. Three rigs are active on infill drilling and on the extension of the Wona SW Zone.

DDH DRILLING WONA AREA
DDH No.ZoneSectionFromToAU* / Length**
WDC224Wona SW15250178.0189.02.74 g/t/11.0 m
WDC225Wona SW15050143.6152.82.07 g/t/9.2 m
WDC226Wona SW15000162.0167.03.17 g/t/5.0 m
WDC226Parallel15000177.0185.02.85 g/t/8.0 m
WDC227Wona SW16700612.0618.03.12 g/t/6.0 m
WDC227Parallel16700323.5324.515.00 g/t/1.0 m
72.60 g/t uncut
WDC227Parallel16700329.6331.65.64 g/t/2.0 m
WDC228Wona SW14550177.0181.01.54 g/t/4.0 m
WDC229Wona17700900.0903.13.44 g/t/3.1 m
WDC229-W1Wona17700920.0924.02.75 g/t/4.0 m
WDC229-W1Parallel177001040.01041.012.30 g/t/1.0 m
WDC230Wona SW14450187.0189.01.90 g/t/2.0 m
WDC231Wona SW14750178.0181.00.67 g/t/3.0 m
WDC232Wona SW16100212.6215.01.64 g/t/2.4 m
WDC233Wona SW16100174.0177.00.76 g/t/3.0 m
WDC235Wona SW14600172.0181.00.78 g/t/9.0 m
WDC237Wona SW15500233.0261.03.49 g/t/28.0 m
Including233.0258.03.60 g/t/25.0 m
WDC238Wona SW15700194.4204.82.81 g/t/10.4 m
WDC240Wona SW15800169.0173.02.95 g/t/4.0 m
WDC241Wona SW15800531.0542.01.42 g/t/11.0 m
WDC243Wona SW15900453.0464.05.31 g/t/11.0 m
6.54 g/t uncut
Including460.0463.011.62 g/t/3.0 m
16.13 g/t uncut
WDC243Parallel15900503.0522.05.02 g/t/19.0 m
Including504.0512.07.16 g/t/8.0 m
WDC245Wona SW16000475.0483.03.39 g/t/8.0 m
WDC248Wona SW16100481.0506.02.41 g/t/25.0 m
WDC250Wona SW16500823.8878.01.64 g/t/54.2 m
Including823.8830.03.58 g/t/6.2 m
WDC250-W1Wona SW16500651.0657.02.52 g/t/6.0 m
WDC253Wona SW15700393.5416.82.62 g/t/23.3 m
WDC255Wona SW15400285.8293.02.43 g/t/7.2 m
WDC256Wona SW15300281.0313.04.17 g/t/32.0 m
5.25 g/t uncut
Including283.0298.06.12 g/t/15.0 m
8.44 g/t uncut
WDC257Wona SW16600712.0720.02.17 g/t/8.0 m
WDC257Wona SW16600687.0691.02.24 g/t/4.0 m
WDC262Wona SW16700713.0715.01.27 g/t/2.0 m
WDC267Wona SW16700525.0530.04.09 g/t/5.0 m
WDC270Wona SW16600521.0537.02.47 g/t/16.0 m
WDC275Wona16500504.8509.04.18 g/t/4.2 m
WDC276Wona16850473.0483.04.02 g/t/10.0 m
WDC277Wona17200562.0565.02.20 g/t/3.0 m
WDC279Wona16950530.0532.04.04 g/t/2.0 m
WDC280Wona17200694.0697.02.58 g/t/3.0 m
WDC281Wona16950549.0557.22.51 g/t/8.2 m
WDC282Wona16950439.0449.04.45 g/t/10.0 m
Including442.0449.05.42 g/t/7.0 m
WDC284Wona SW15700341.0392.02.27 g/t/51.0 m
Including386.0392.06.25 g/t/6.0 m
WDC285Wona SW15650212.0219.06.46 g/t/7.0 m
WDC286Wona SW15650253.0266.04.13 g/t/13.0 m
WDC287Wona SW15650339.0368.02.24 g/t/29.0 m
Including357.0360.05.10 g/t/3.0 m
*All values above 15 g/t Au are cut at 15 g/t Au.
**All lengths are measured along the hole axis; additional information is required to determine true widths.

The feasibility study of the underground project lowered the bottom of the underground mine by some 90 meters compared with the pre-feasibility planning, to an elevation of 4,770 meters. Accordingly, the very deep exploration drilling program is pushed deeper, with the remaining portion requiring higher grades to achieve economic viability. Infill drilling in the southwest, above 4,770 EL, will increase due to the ease of transformation to reserves, therefore requiring a more significant portion of the drilling program and thus slowing the investigation of the very deep area.

Kona

Recent infill drilling at Kona provides more precision to the reserves and surrounding resources, confirming year-end technical report estimations and ore distribution (ref. Annex 1: Kona Zone Reverse-Circulation Drill Results: http://media3.marketwire.com/docs/Kona.pdf). This program remains in progress.

The exploration programs were designed and managed locally by Dofinta Bondé and David Lalonde, Mana Mineral's Exploration Chief Geologists and Richard Roy P.Geo, Exploration Manager, and guided and supervised under the direction of Michel Crevier, P.Geo MScA, Geology Manager and SEMAFO's Qualified Person who has reviewed this press release for accuracy and compliance with National Instrument 43-101.

For core drilling, all individual samples represent approximately one-meter in length of core, which was sawed in half. Half of the core is kept on site for reference and its counterpart is sent for preparation and gold assaying at the ALS Chemex laboratories in Ouagadougou, Burkina Faso. For RC drilling, all individual samples represent approximately one meter in length of rock chips homogenized and riffle-split to an approximately 2-kilogram subsample, which is sent for preparation and gold assaying at the ALS Chemex laboratories in Ouagadougou, Burkina Faso. Each sample (core and RC) is fire-assayed for gold content on a 50-gram sub-sample at the same ALS Chemex laboratories. In addition to ALS Chemex's own QA/QC (Quality Assurance/Quality Control) program, an internal quality control and quality assurance program is in place throughout the sampling program, using blind duplicates, blanks and recognized industry standards.

About SEMAFO

SEMAFO is a Canadian-based mining company with gold production and exploration activities in West Africa. The Company currently operates three gold mines: the Mana Mine in Burkina Faso, the Samira Hill Mine in Niger and the Kiniero Mine in Guinea. SEMAFO is committed to evolve in a conscientious manner to become a major player in its geographical area of interest. SEMAFO's strategic focus is to maximize shareholder value by effectively managing its existing assets as well as pursuing organic and strategic growth opportunities.

Caution Concerning Forward-looking Statements

This press release may contain forward-looking statements. Forward-looking statements involve known and unknown risks, uncertainties and assumptions and accordingly, actual results and future events could differ materially from those expressed or implied in such statements. You are hence cautioned not to put undue reliance on forward-looking statements. Forward-looking statements include words or expressions such as "further", "expand", "expected", "in-progress", "potential", "believed", "committed", "evolve", "become", "pursuing" and other similar expressions. Factors that could cause future results or events to differ materially from current expectations expressed or implied by the forward-looking statements include the ability of the recent drilling over the Wona SW zone to expand underground reserves from those reported in the Mana Underground Feasibility Study, the ability of the recent and ongoing drilling to increase reserves on the southern-most side of the Wona SW zone, the ability to execute on our strategic focus, variation in the price of gold and currencies, mining industry risks, uncertainty as to calculation of mineral reserves and resources, delays, political and social stability in Africa (including our ability to maintain or renew licenses and permits) and other risks described in SEMAFO's documents filed with Canadian securities regulatory authorities. You can find further information with respect to these and other risks in SEMAFO's 2010 Annual MD&A, and other filings made with Canadian securities regulatory authorities and available at www.sedar.com. These documents are also available on our website at www.semafo.com. SEMAFO disclaims any obligation to update or revise these forward-looking statements, except as required by applicable law.

A map is available at the following address: http://media3.marketwire.com/docs/semafo0512.pdf

Contact Information:

SEMAFO
Benoit La Salle, FCA
President & CEO
514-744-4408
Toll-Free:1-888-744-4408
blasalle@semafo.com

Sofia St Laurent
Communications
(514) 744-4408
Toll-Free:1-888-744-4408
sstlaurent@semafo.com