Calibre Mining and B2Gold Sign Definitive Joint Venture Agreement

Calibre Mining Corp. (TSX VENTURE:CXB) (the "Company" or "Calibre") is pleased
to announce that the Company has signed a definitive Joint Venture Agreement
(the "JV Agreement") with B2Gold Corp. ("B2Gold") granting B2Gold an option to
acquire a further 19% interest in and to the Primavera Gold-Copper Porphyry
Project containing a total of 322 km2 of mineral concessions (together, the
"Project") in north-east Nicaragua. Calibre currently controls a 49% interest in
the Project, while B2Gold controls a 51% interest and is project operator. In
addition to this joint venture with B2Gold, Calibre controls a 100% interest in
463 km2 of mineral concessions in the Mining Triangle of northeast Nicaragua
which includes the recent, high-grade gold discovery at the Montes de Oro
Project. 


The JV Agreement dated September 9, 2013 allows B2Gold to earn an additional 19%
interest in and to the Project for a total interest of 70% by spending $6.0
million in additional project expenditures over 36 months (3 years). The JV
Agreement supersedes and replaces the original Option Agreement between Calibre
and B2Gold (entered into in June 2009 and amended in July 2010 and October 2010)
which has now been terminated. 


Greg Smith, President and CEO stated, "The signing of the Joint Venture
Agreement with B2Gold is an important step forward for the Primavera Gold-Copper
Porphyry Project. As previously announced, B2Gold has initiated a $2.0 million
program on the Primavera Project to expand the existing high grade gold-copper
mineralized zone and to locate additional gold and copper discoveries within the
322 km2 Borosi mineral concessions. We are very pleased to have B2Gold as
Calibre's partner in the Primavera gold-copper discovery and look forward to
significantly advancing the Project under the JV Agreement." 


Significant terms of the Joint Venture Agreement are as follows:



--  Calibre has granted B2Gold an option (the "Option") to acquire an
    additional 19% interest in and to the Project for a total interest of
    70% in the Project by incurring CDN$6,000,000 in additional exploration
    and development expenditures on the Property over 36 months (3 years).
    Each (12 months) of the Option B2Gold must incur a minimum of $1.5
    million of exploration and development expenditures on the Property.
    Expenditures incurred by any date in excess of the aggregate amount of
    expenditures required to be incurred by such date shall be carried
    forward to the succeeding period or periods and qualify as expenditures
    for such succeeding period or periods.

--  Upon the exercise of the Option by B2Gold, B2Gold and Calibre shall
    share all further exploration and development expenditures on the
    Property on a 70% (B2Gold)/30% (Calibre) basis. B2Gold will be project
    operator. 

--  B2Gold shall only get credit towards the CDN$6,000,000 in required
    expenditures to exercise the Option for expenditures incurred on the
    Property after April 24, 2013. 



Calibre's New High Grade Gold Discovery at Montes de Oro

Calibre recently announced trench results including 7.1 g/t gold over 52.3
metres from the new, high-grade gold discovery at Calibre's 100% owned Montes de
Oro project - see News Release dated August 15, 2013. Further sampling
consisting of additional trenching, extensions to open ended trenches and an
expanded soil grid has been completed and results are expected over the next few
weeks.


About Calibre Mining Corp.

Calibre Mining Corp. is a TSX Venture Exchange listed company (TSX VENTURE:CXB)
that is focused on the acquisition, exploration and development of gold, silver
and copper deposits in Central America. The Company is focused on its 100% owned
Riscos de Oro and Cerro Aeropuerto gold-silver deposits, the exploration program
at the Montes de Oro high grade gold discovery, the exploration program at the
Primavera gold-copper project in conjunction with B2Gold Corp. and the
exploration program on the Rosita copper-gold-silver project in conjunction with
Alder Resources Ltd. Major shareholders of Calibre include gold producer B2Gold
and investment fund Sun Valley Gold.


Calibre Mining Corp.

Greg Smith, P.Geo., President and CEO

Neither the 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.


FOR FURTHER INFORMATION PLEASE CONTACT: 
Calibre Mining Corp.
Ryan King
Vancouver, Canada
604-628-1012
www.calibremining.com