On Monday, Andrey Karlov was killed by Turkish off-duty police officer Mevlut Mert Altintas at an art gallery exhibition opening in Ankara. Three more people were also injured in the attack. The Russian Foreign Ministry said it considered the attack a terrorist act.
Mevlut Mert Altintas' father, mother, sister, two uncles and one of their wives have been released after testimony, the CNN Turk broadcaster cited law enforcement sources as saying.
A farewell ceremony for the Russian ambassador is expected to take place on Thursday in the Russian capital, with President Vladimir Putin is expected to attend.
