Armenia says one of its Soviet-made S|U-25 fighter jet was shot down by a Turkish F-16 in Armenian air space, escalating the conflict over disputed Nagorno-Karabakh region.
Turkey, which is baking the Azerbaijan in the conflict has denied the claim.
Over 100 people including civilians, have died in three days of fighting over the disputed mountainous region. The enclave is internationally recognised as part of Azerbaijan but has been run by ethnic Armenians since a 1988-94 war between the former Soviet republics.
Azerbaijan has repeatedly stated that its air force does not have F-16 fighter jet, however, Turkey does.
Turkey backs Azerbaijan, Russia which has a military base in Armenia is also friendly with Azerbaijan, has called for an immediate ceasefire.
Armenian Defence Ministry spokeswoman Shushan Stephanyan said the Armenian SU-25 was shot down on Tuesday morning and the pilot died heroically, Alleging Turkish F-16 encroaching 50km (37 miles ) deep into Armenian air space