Funeral begins for slain Russian ambassador to Turkey

The funeral service started Thursday for Andrei Karlov, the Russian ambassador to Turkey who was slain by a police officer while making a speech at an art gallery in the Turkish capital on Monday.

A farewell ceremony was being held at the Russian Foreign Ministry in Moscow, amid heightened security.

Russian President Vladimir Putin is expected to attend and Patriarch Kirill, the head of the Russian Orthodox Church, will hold a prayer service at the Cathedral of Christ the Savior before the burial, the state-owned TASS news agency reported.

Karlov’s body was returned to Moscow late Tuesday after he was shot multiple times by a Turkish police officer in Ankara. The gunman, Mevlüt Mert Altıntaş, 22, shouted slogans related to the nearly 6-year-old civil war in Syria before he was shot and killed by police.

Investigators from Russia have traveled to Turkey to investigate the incident.

Turkey’s President Tayyip Recep Erdogan said Wednesday that Altıntaş was a follower of Fethullah Gülen, a U.S.-based Turkish cleric who has been living in self-imposed exile in Pennsylvania since 1999.

Erdogan blames Gülen for a failed coup in July that left 290 people dead and thousands arrested and wants him extradited to stand trial.

Gülen condemned Karlov's assassination, describing it as a "heinous act of terror."

"No terrorist act can be justified, regardless of its perpetrators and their stated purposes," he said in an online statement.