An Azerbaijani army officer has been killed by Armenian forces on the frontline close to the disputed region of Nagorny Karabakh, the defence ministry in Baku said on Saturday. The Azerbaijani lieutenant died after a bullet hit him in the head on Friday, a defence ministry spokesman told AFP, in the latest deadly incident caused by regular exchanges of fire along the frontline. Named as Lieutenant Elshad Gasanov, he was the 14th soldier to be killed this year amid continued tensions over the mountainous region. Ethnic Armenian separatists backed by Yerevan seized Nagorny Karabakh from Azerbaijan in a conflict in the 1990s that left around 30,000 dead. Azerbaijan has repeatedly threatened to use force to win back Karabakh if internationally mediated peace negotiations do not yield satisfactory results, while Yerevan has warned of large-scale retaliation if Baku launches any military action.