An explosive device blew up Thursday inside the U.S. embassy compound in Ukraine’s capital.

The device was thrown over the Kiev embassy compound’s fence after midnight, according to police, before exploding.

{mosads}No one was hurt in the incident, which police are calling a terrorist attack.

The State Department issued a travel warning for the eastern Ukrainian regions of Donetsk and Luhansk in December, as well as Crimea, citing violent clashes between the Ukrainian government and Russian-backed separatists. Kiev is in the north-central part of the country.