In an address to the nation, Azerbaijani President Ilham Aliyev says Armenia has "violated" the US-brokered ceasefire. But Armenia's defence ministry says Azerbaijani forces have violated the truce with artillery fire on combat positions in various parts of the frontline. A third attempt at halting weeks of fighting over Nagorno-Karabakh has collapsed quickly with Armenia and Azerbaijan trading accusations of violating the ceasefire within minutes.