By Ali Cura

KIEV, Ukraine

 A bomb attack targeted early Thursday the U.S. embassy in Ukraine, the Kiev Police Department said.

No casualties were reported after an unidentified perpetrator threw an explosive device into the compound of the diplomatic mission, it said. 

An operation is underway to nab the attacker, it said, calling the attack "an act of terrorism".

The U.S. embassy confirmed on its Facebook account that there was a "security incident" involving a "small incendiary" device after midnight at the compound.

It said there was no damage to the property and no personnel were injured. 

"At this time, we do not consider this incident a terrorist act. The Embassy is working closely with our local partners, and the investigation is ongoing," the statement added.

*Diyar Guldogan contributed to this report from Ankara.