By Peter Hobson
MOSCOW (Reuters) - Russia staged a somber funeral ceremony on Thursday for Andrei Karlov, the Russian ambassador to Turkey who was shot dead in Ankara by a man who shouted "Allahu Akbar" and "Don't forget Aleppo".
President Vladimir Putin, who promised retribution after Karlov, 62, was killed on Monday, was among mourners, including relatives and fellow diplomats, who gathered at the Foreign Ministry building where the slain envoy's body lay in an open casket in Russian Orthodox tradition.
Russia and Turkey say the assassination was a failed attempt to derail a rapprochement between Moscow and Ankara which has seen them cooperate more closely over Syria, even though they have backed different sides in the conflict.
Prime Minister Dmitry Medvedev and Foreign Minister Sergei Lavrov laid flowers near Karlov's body in a ceremony in the marbled lobby of the looming Stalin-era skyscraper in central Moscow. Lavrov said Karlov had been the victim of "a despicable terrorist act".
Putin, who has said he knew Karlov personally and posthumously awarded him the highest military medal of Hero of Russia, paid his respects, briefly sitting beside the coffin and speaking to Karlov's widow.
Karlov was a Soviet-trained diplomat who worked in North and South Korea during the 1990s and 2000s and was sent to Turkey in 2013.
His name was etched into a slab of pink marble on the wall of the foreign ministry building commemorating Russian diplomats killed in the line of duty.
Proceedings moved to Moscow's gold-domed Christ the Saviour Cathedral later on Thursday where the head of the Russian Orthodox Church, Patriarch Kirill, led a ceremony.
"He will go down in the history of the Fatherland," said Kirill.
The envoy was buried later on Thursday in a cemetery in a northern Moscow suburb with military honors, his coffin draped in the Russian flag.
"We must know who directed the killer's hand," Putin said after Karlov was assassinated.
Turkish authorities have identified the assassin as Mevlut Mert Altintas, 22, who had worked for Ankara's riot police. He was later killed by security forces.
President Tayyip Erdogan has blamed the killing on the network of Muslim cleric Fethullah Gulen, something Gulen denies. The Kremlin however has said it is too early to say who stood behind the murder.
Russia has flown a team of investigators to Turkey to help with the investigation.
(Editing by Andrew Osborn and Richard Balmforth)