Calibre Reports Trench Results From Borosi Gold-Copper Concessions, Nicaragua

Apr 22, 2010

Vancouver, British Columbia: Calibre Mining Corp. (TSX-V: CXB) (the "Company" or "Calibre") is pleased to report assay results from channel sampling of trenches, and the commencement of drilling at the La Luna gold-silver project located within Calibre's 100% owned Borosi gold-copper concessions in northeast Nicaragua.

La Luna Project
The drill program at La Luna will follow up on improved assay results from recently re-sampled quartz veins in trenches. To obtain a better representative sample of the quartz veins, channel samples from the trenches were cut by saw rather than previously reported chip sampling methods (see news release February 3, 2010 and March 31, 2010). In addition, the channel samples were assayed by both the atomic absorption (AA) method as well as the more comprehensive gravimetric method. The channel samples, on average, have returned a 35% increase in gold grade (based on a gravimetric finish) and an 11% interval increase over the chip samples. Trench results from channel sampling and the previously released chip sampling are outlined below.

La Luna Project - Trench Assay Results

 

 

Channel Sample

 

Chip Sample*

 

 

 

Interval

 

AA

 

Gravimetric

 

AA

 

Interval

 

Trench

 

From
(m)

 

To
(m)

 

Metres

 

Gold
(g/t)

 

Silver
(g/t)

 

Gold
(g/t)

 

Silver
(g/t)

 

Gold
(g/t)

 

(m)

 

BTR10-010

 

11.50

 

16.00

 

4.50

 

2.51

 

7.61

 

2.57

 

3.63

 

2.25

 

3.70

 

BTR10-011

 

8.50

 

11.70

 

3.20

 

4.62

 

194.40

 

4.93

 

191.80

 

3.92

 

3.20

 

BTR10-012

 

7.80

 

10.40

 

2.60

 

2.46

 

75.48

 

3.20

 

90.01

 

3.11

 

2.10

 

BTR10-017

 

7.50

 

10.20

 

2.70

 

3.85

 

38.12

 

3.77

 

36.85

 

1.45

 

2.30

 

*previously released

The diamond drill program at La Luna will test a zone of gold-bearing epithermal quartz veins and quartz breccias. These veins and breccias were delineated over a strike length of 1,100 metres through a soil sampling program and a series of five trenches. Mineralized intercepts from those five trenches average 3.62 g/t Au and 66 g/t Ag over 3.4 metres. Drilling at La Luna will also test the depth extent of a zone associated with an historical small open cut which assayed 3.5 g/t gold over 12.6 metres. Diamond drilling results will be reported when received and compiled.

2009/2010 Borosi Exploration Program
The 26 hole, 6,000 metre diamond drill program at the Borosi concessions consists of drill testing three projects: the Bambana project, the La Luna project and the Riscos de Oro project. In addition, systematic exploration of other high priority prospects at Borosi will be ongoing to further define drill targets.

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.

The Borosi gold-copper 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.

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.

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
www.calibremining.com

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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