Calibre Intersects 14.05 G/T Gold And 1,990.00 G/T Silver Over 0.8 Metres At The Borosi Property, Nicaragua

June 1, 2010

Vancouver, British Columbia: Calibre Mining Corp. (TSX-V: CXB) (the "Company" or "Calibre") is pleased to announce high grade gold and silver assay results from its initial drill program on both the La Luna and Riscos de Oro epithermal gold-silver projects within the 100% owned Borosi Gold-Silver-Copper Concessions in northeast Nicaragua. Highlights of the drilling include 12.20 g/t gold and 105.10 g/t silver over 2.6 metres in hole LL10-002 from La Luna and 14.05 g/t gold and 1,990.00 g/t silver over 0.8 metres in hole RD10-001 from Riscos de Oro.

Robert Brown, President and CEO stated: "The La Luna and Riscos de Oro results are significant as they represent Calibre's first drill test on two epithermal gold-silver systems each of which has been traced on surface for over 2.0 kilometres on the Borosi concessions. The initial drill results confirm the depth continuity of epithermal gold-silver mineralization intersected in surface trenches and historic workings on the two projects. A third drill rig has arrived on the property to assist in delineating the extent of the mineralized zones along strike and at depth."

Table 1: Highlights of Borosi Diamond Drilling Results

Project Drill Hole From (m) To
(g/t Au)
(g/t Ag)
(% Cu)
La Luna LL10-001 115.70 123.45 7.75 1.43 7.51 -
  LL10-002 90.00 99.00 9.00 4.63 39.75 -
  Including 90.00 97.00 7.00 5.88 50.16 -
  Including 92.40 95.00 2.60 12.20 105.10 -
Riscos de Oro RD10-001 177.60 183.40 5.80 2.44 292.60 -
  Including 177.60 178.40 0.80 14.05 1990.00 -
    186.10 190.25 4.15 1.01 - -
Bambana BB10-001 71.50 73.50 2.50 - 28.15 1.05
    79.00 121.00 42.00 - - 0.43
  BB10-002 58.10 58.65 0.55 9.02 75.50 0.11
    75.40 86.90 11.50 0.25 10.41 0.51
  Including 75.40 78.62 3.22 0.23 21.81 1.15
    83.15 86.90 3.75 0.55 12.39 0.54

No significant results

La Luna Project

La Luna is a northwest trending, gold and silver bearing, epithermal quartz vein system which has been delineated for over 2.0 kilometres through a soil sampling and trenching program. The initial drill program is testing the depth extent of mineralization below a small historic open cut in the southern zone and along strike in the northern zone. Drilling below the small open cut at the southern end of La Luna returned 5.88 g/t gold and 50.16 g/t silver over 7.0 metres (LL10-002) and has confirmed mineralization to a depth of 82 metres below surface. The vein is open at depth and along strike and has been intersected in follow up hole LL10-004 (assay results pending) drilled approximately 110 metres below surface from the same collar location as LL10-002.

The first drill hole in the northern zone (700 metres north of LL10-002) returned 1.43 g/t gold and 7.5 g/t silver over 7.75 metres (LL10-001) at a depth of approximately 100 metres below trench BTR10-009. Six more drill holes will further test this northern section, following up on results from recent trenching that include BTR10-011: 4.93 g/t gold, 191.8 g/t silver over 3.2 metres and BTR10-012: 3.2 g/t gold and 90.01 g/t silver over 2.6 metres (see April 21, 2010 news release). Assays from the northern holes are pending.

Riscos de Oro Project

Riscos de Oro is a northeast trending, low sulphidation epithermal gold-silver quartz vein system that has been traced on surface for over 2.0 kilometres. Riscos de Oro was previously mined by both open pit and underground methods from 1972 through to 1981. The main ore shoot at Riscos de Oro was only mined down to a 300 foot level (approximately 93 metres) below surface. Calibre's first drill hole at Riscos de Oro (RD10-001) has intersected this zone at a vertical depth of 155 metres (approximately 508 feet) below surface, returning 2.40 g/t gold and 292 g/t silver over 5.80 metres, including 14.05 g/t gold and 1,990.00 g/t silver over 0.80 metres, confirming the continuation of high grade gold-silver mineralization at a depth of 62 metres below the last known workings on the project. This zone remains open at depth and along strike and is currently being tested by a further three drill holes.

A third drill rig has arrived on the project and will test along strike of the main Riscos de Oro vein while the second rig continues testing the main ore shoot at depth.

Bambana Project

The Bambana project is located four kilometres northwest of the past producing Santa Rita copper mine, a copper skarn deposit that is estimated to have produced 305 million pounds of copper over the mine life. The Bambana drill program tested two areas. The first area is a 500 metre by 300 metre area associated with artisanal gold workings and a small prospecting pit. Two drill holes on his target returned 0.43% Cu over 42 metres (BB10-001) and 9 g/t gold and 75.5 g/t silver over 0.55 metres (BB10-002). The third drill hole tested a northeast trending structure but returned no significant values.

Borosi Concessions

The Borosi concessions cover approximately 71,000 hectares within the historic Mining Triangle of Nicaragua. The concessions are subject to an option agreement, whereby B2Gold may earn an initial 51% in the Borosi concessions by completing C$8 million in exploration expenditures over a period of three years. The Borosi exploration budget through July 2010 is C$2.5 million, with Calibre acting as operator.

Quality assurance and quality control procedures include the systematic insertion of blanks, standards and duplicates into the soil and rock sample strings. Samples are placed in sealed bags and shipped directly to ALS CHEMEX labs in North Vancouver, BC for gold fire assay and ICP multi element analyses. The technical content in this news release was read and approved by Roger March, P.Geo., a professional geologist registered in the Province of Newfoundland & Labrador and a qualified person as defined by NI 43-101.

Calibre Mining Corp. is an aggressive, well financed, TSX Venture Exchange listed company (TSX.V: CXB) that is focused on the acquisition, exploration and development of gold and copper deposits in Central America. Major shareholders of Calibre include gold producers Yamana Gold Inc. and Kinross Gold Corp.

1 From Arengi et al (2002).

Calibre Mining Corp.

Signed "Robert Brown"

Robert D. Brown, B.Sc., MBA
President and CEO

For further information contact:
Joyce Musial - Vancouver, Canada
604 681 9944

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

Cautionary Note Regarding Forward Looking Statements
Safe Harbor Statement under the United States Private Securities Litigation Reform Act of 1995: Except for the statements of historical fact contained herein, the information presented constitutes "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements including but not limited to those with respect to the price of gold, silver or copper, potential mineralization, reserve and resource determination, exploration results, and future plans and objectives of the Company involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievement of Calibre Mining Corp. to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. There can be no assurance that such statements will prove to be accurate as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.


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