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

VANCOUVER, BRITISH COLUMBIA, Apr 22 (MARKET WIRE) --
Calibre Mining Corp. (TSX VENTURE: 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(i)
----------------------------------------------------------------------------
Interval AA Gravimetric AA Interval
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Trench From Gold Silver Gold Silver Gold
(m) To (m) Metres (g/t) (g/t) (g/t) (g/t) (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
----------------------------------------------------------------------------
(i)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 VENTURE: 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.

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

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.

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.

Contacts:
Calibre Mining Corp.
Joyce Musial
604 681 9944
www.calibremining.com

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