Turkish police on Tuesday detained a man who fired shots in front of the U.S. embassy in Ankara, several hours after the Russian ambassador to Turkey was killed in an attack across the street.
The man took out a pump-action shotgun he hid in his coat and fired around eight shots in the air before the embassy's security guards intervened and apparently overpowered him, according to the state-run Anadolu news agency.
No one was hurt in the incident which occurred hours after a Turkish policeman, appearing to condemn Russia's military role in Syria, fatally shot Russian Ambassador Andrei Karlov in front of a shocked gathering at a photo exhibit.
The embassy said its missions in Ankara, Istanbul and the southern city of Adana would be "closed for normal operations on Tuesday."
The U.S. embassy is located just across the street from the art exhibition center where the Russian ambassador was killed. It was not immediately known if the two incidents were connected.
The leaders of Turkey and Russia have described the attack as an attempt to disrupt efforts to repair ties between their countries, which have backed opposing sides in the Syrian civil war.
It came as the foreign and defense ministers from Turkey, Iran and Russia prepared to hold a key meeting on Syria on Tuesday in Moscow.
The assassination occurred after days of protests by Turks angry over Russia's support for Syrian President Bashar Assad and Russia's role in the bombardment and destruction of Aleppo, Syria's largest city.
An Associated Press photographer and others at the art gallery watched in horror as the gunman, who was wearing a dark suit and tie, fired at least eight shots, at one point walking around the ambassador as he lay motionless and shooting him again at close range.
The assailant, who was identified as Mevlut Mert Altintas, a 22-year-old member of Ankara's riot police squad, was later killed in a shootout with police.
A group of 18 investigators and foreign ministry officials have left for Ankara to investigate the killing, Russian President Vladimir Putin's spokesman, Dmitry Peskov, said after Turkish President Recep Tayyip Erdogan said he had accepted during a telephone conversation with Putin a request that Russian experts take part. Anadolu reported that the Russian officials would participate in the autopsy.