Mineralization Extended Over 600 M From The Alta Ley And El Gallo Areas Of Sierra Metals' Bolivar Mine, Chihuahua Mexico

VANCOUVER,May 14, 2013/CNW/ -Sierra Metals Inc. (TSX-V:SMT) (BVL:SMT) ("Sierra Metals" or the "Company" previouslyDia BrasExploration) is pleased to announce that drilling has encountered wide zones of mineralization in both the Upper and Lower Skarn horizons located 600 m northwest of the major ore-hosting zones of the Bolivar (Alta Ley) Mine. In addition, step-out drilling from the El Gallo deposit has extended that mineralized zone 600 m to the northeast with high grades of zinc in the Upper Skarn horizon.

Daniel Tellechea, President and CEO of Sierra Metals, commented:"Sierra Metals continues to expand the Bolivar ore deposits through its aggressive exploration drilling program. These results support our contention that the Bolivar mine is only partially explored and that significant additional mineralization remains to be discovered. While our recent reserves statement provided a snapshot of Bolivar's mineralization at that time, we expect to increase reserves and resources during this year with the objective of commissioning a NI 43-101 update at the end of 2013."

Recent Drilling Results

Bolivar NW Area:This area (http://files.newswire.ca/1167/EN-1SMMay14013.jpg) is located northwest of theAlta LeyMine and hosts manto-type mineralization in both the Upper and Lower Skarns, which are the prominent mineralized horizons in the Bolivar Mine area. Very little drilling had been done in this area before this year and results to date indicate the mineralized horizons extend hundreds of meters to the northwest and northeast.

Assay results are shown in the table below:

SectionsDB13B425andDB13B433show the relationships of these drill holes and their mineralized intervals. From theAlta Leymine to the northwest, the mineralized horizons extend for at least 600 m to the northwest and for a width of at least 250 m.

"Step Out" Area:This area is located 600 m northeast of the El Gallo deposit which is one of the areas currently being mined by the Company. These drill holes were placed where the Nathalie and Fernandez Trend faults converge, and where the Increíble breccia pipe occurs. The high zinc values in these holes demonstrate that the Upper Skarn horizon, the same horizon that hosted high grades of copper and zinc in theAlta LeyMine, is strongly mineralized in this area.

For example, the intercepts in holes 416 & 424, combined with 426 (assays pending) indicate a 100-m long zone of Upper Skarn zinc mineralization that is open both directions along strike and to depth. Additional drilling will be done to determine the extent of this zone. These holes were drilled towards the Increíble breccia pipe in a north-westerly direction and were not oriented properly to test mineralization related to the Nathalie Fault but did intercept "high-value" skarn mineralization of the type targeted in the Company's drill program for 2013. These intercepts, however, are in the area that is inferred to host "high-value" deposits, namely in the vicinity of the Nathalie Fault.

New holes in progress are oriented specifically to test for "high-value" deposits and drilling is planned to continue through 2013 with the objective of discovering "high-value" deposits, namely deposits with Cu+Zn grades of 15-20%, the type encountered in drill hole 416.

Drill results include the following:

Implications

Drilling up to 600 m both to the northwest and northeast of the Company's active mining areas of El Gallo andAlta Leyhas shown potentially mineable ore grades and widths in the Upper and Lower Skarn horizons, clearly demonstrating that the limits of mineralization have not been reached.

Management of Sierra Metals believes that the deposits at El Gallo,Alta Leyand other areas have additional potential for expansion and the Company is conducting an aggressive drilling program to explore these areas further.

The ongoing drilling program will continue to test these new mineralized horizons and high value targets. Two drills are currently in operation on the surface and one drill underground; 14,970 meters are scheduled to be drilled in 2013.

The 7.46 million tonnes of Proven and Probable Reserves grading 19.52 g/t Ag, 0.76% Cu, 0.33% Zn and 0.12 g/t Au (see press release ofApril 24, 2013), and 15.40 million tonnes of Measure and Indicated Resources grading 19.45 g/t Ag, 0.79% Cu, 1.06% Zn and 0.24 g/t Au (see press release ofAugust 30, 2012) at Bolivar represent a significant but unknown portion of the extensive mineralization that occurs in the area.

Method of Analysis

Samples were prepared at the ALS Chemex lab facility in Chihuahua,Mexico, and analyzed by ICP and AA methods at their facilities inVancouver,Canada. Diamond drill samples sent for analysis consisted of half HQ-size and NQ-size diamond core split on site, prepared by the ALS Chemex sample preparation laboratory in Chihuahua,Mexico, and assayed for Au by 50 g fire assay with AA finish, and for Ag by AA on 50 g split sample at the ALS Chemex NorthVancouverLaboratory. Assays for Pb, Zn and Cu are analyzed by Induction Coupled Plasma (ICP) at ALS Chemex.

Quality Assurance

The technical content of this news release has been approved by Thomas L. Robyn, Ph.D., CPG, RPG, a Qualified Person as defined in NI 43-101 and Senior Vice President, Exploration, for Sierra Metals Inc.

About Sierra Metals

Sierra Metals Inc. is a Canadian mining company focused on precious and base metals from its Yauricocha mine inPeru, and its Bolivar and Cusi mines inMexico. In addition, Sierra Metals is exploring several precious and base metal targets inPeruandMexico. Projects inPeruinclude Adrico (gold), Victoria (copper-silver) and Ipillo (polymetallic) at the Yauricocha Property in the province of Yauyos and the San Miguelito gold properties in NorthernPeru. Projects inMexicoinclude Bacerac (silver) in the state of Sonora, La Verde (gold) at the Batopilas Property in the state of Chihuahua, and Las Coloradas (silver) at the Melchor Ocampo Property in the state of Zacatecas.

The Company's shares trade on the Bolsa de Valores de Lima and TSXV under the symbol "SMT".

This press release does not constitute an offer to sell or solicitation of an offer to buy the securities in the United States or any other jurisdiction. The Common Shares will not be and have not been registered under the United States Securities Act of 1933, as amended, and may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements.

Neither the TSXV nor its Regulation Services Provider (as that term is defined in policies of the TSXV) accepts responsibility for the adequacy or accuracy of this release.

Forward-Looking Statements

Except for statements of historical fact contained herein, the information in this press release may constitute "forward-looking information" within the meaning of Canadian securities law. Other than statements of historical fact, all statements are "forward-looking statements", which involve various known and unknown risk and uncertainties and other factors, including market conditions that may affect the Company's ability to execute its current business plan. Actual results might differ materially from results suggested in any forward-looking statements. The Company assumes no obligation to update the forward-looking statements, or to update the reasons why actual results could differ from those reflected in the forward-looking statements unless and until required by securities laws applicable to the Company. Additional information identifying risks and uncertainties is contained in filings by the Company with the Canadian securities regulators, which filings are available atwww.sedar.com.

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SOURCE: Sierra Metals Inc.

For further information:

For further information on Sierra Metals, please visit www.sierrametals.comor contact:

Daniel Tellechea
President & CEO
Sierra Metals Inc.
1 (866) 493‐9646

Matt Morrish
Director, Investor Relations
Sierra Metals Inc.
1 (866) 493‐9646