MOSCOW (AP) — Police in the Ukrainian capital Kiev say someone has hurled an explosive device onto the grounds of the U.S. embassy.

Police said in a statement on Thursday no one was injured when the device detonated on the embassy's lawn in the late hours on Wednesday. The U.S. embassy's compound on the western outskirts of Kiev is surrounded by a high fence, making it difficult for a passer-by to hurl something there.

Police did not identify the explosive device but said they were treating the incident as an act of terrorism.