Azerbaijan has admitted mistakenly shooting down a Russian Mi-24 military helicopter over Armenia, killing two crew members and injuring a third.
In a statement, Azerbaijan apologised, offering to pay compensation.
Russia said a missile downed its Mi-24 accompanying a column of Russian troops in Armenia, where Russia has a base.
It comes amid fierce fighting between Azerbaijan and Armenian separatists for Nagorno-Karabakh. But the helicopter was not downed near those clashes.