BAKU : Armenian troops on Saturday killed an Azerbaijani soldier in a fresh border clash, Azerbaijan officials said, as tensions mounted over a separatist region. The soldier ‘was killed in action as the Armenian forces attempted to attack Azerbaijani army positions,’ the defence ministry in Azerbaijan's capital Baku said. ‘Armenia's military and political leadership bears responsibility for the provocations along the frontline,’ the ministry said. ‘From now on, our retaliatory measures will be even tougher.’ Azerbaijan and Armenia are locked in a decades-long conflict over Nagorny Karabakh, an ethnic Armenian enclave in Azerbaijan.