Azerbaijan's defence ministry announced on Sunday it was callig a unilateral ceasefire in Nagorno-Karabakh as fighting in the disputed region entered its second day.

Azerbaijan took the decision after international calls to end the fighting, Radio Free Europe/Radio Liberty informs.

Baku added that it will start strengthening its positions on territory it has gained since Saturday.

Clashes on Saturday claimed the lives of at least twelve Azerbaijani servicemen, eighteen Armenian troops and two civilians.

Azerbaijan warned that it will return fire if attacked by Armenian forces or ethnic Armenian separatists.

Sporadic fighting has been reported on Sunday after the major combat operations which took place on Saturday.

Armenia and Azerbaijan have been hurling mutual accusations at each other for violating the ceasefire and the outbreak of fighting.

Baku blamed Yerevan for violating the 21-year-old ceasefire more than 130 times, including artillery attacks from both Armenian territory and from within the disputed region.

Azerbaijan claimed its forces returned fire after being attacked in several districts.

In exchange, Armenia accused Azerbaijan of launching major offensive on Saturday using tanks, heavy artillery and helicopter gunships.

Turkish President Recep Erdogan expressed his support for Azerbaijan, vowing to back the country to the end.

Russia, the USA and OSCE have all called on both sides to end to hostilities and respect the ceasefire.

The co-chairs of the OSCE Minsk Group, which is acting as a mediator in the conflict, are planning to meet in Vienna on Monday.