Police in Montenegro said Thursday they are “working intensely” to identify an assailant who threw an explosive device into the U.S. embassy compound in the capital, Podgorica, before killing himself.

Police said in a statement that the man threw a bomb into the embassy yard and then committed suicide by activating another one around midnight Wednesday.

The blast created a crater but caused no other material damage to the embassy property, the statement said.

Police sealed off the area around the embassy after the explosion.

Officers came to the scene after receiving reports about an explosion and found a lifeless male body in the area of the Moraca river that runs through Podgorica, the statement said.

The U.S. State Department has said embassy officials are working with police to identify the assailant. The embassy in Podgorica said Thursday all staff are safe and accounted for after the incident.

Montenegro borders the Adriatic Sea in southeastern Europe. It joined NATO last year despite strong opposition from its traditional Slavic ally Russia.

Several people, including two Russian secret service operatives, are on trial in Podgorica on charges that they wanted to overthrow Montenegro’s government in 2016 because of its pro-Western policies.

The U.S. established diplomatic ties with the tiny Balkan state in 2006 after it split from much larger Serbia.

(AP)