The area was sealed off as police swarmed on the embassy after the blasts sparked a “security situation” in the Balkan state’s capital of Podgorica shortly before midnight on Wednesday.
The assailant died after detonating the second device but no one else was harmed and no major damage was caused to the building, according to reports.
A US State Department spokeswoman said embassy officials were working with local police to identify the attacker and were still trying to confirm all staff were safe.
The embassy warned US citizens in the city to stay away from the embassy and to avoid large gatherings while police continued to investigate.
In a statement posted on social media, it said the embassy’s visa services would be cancelled today and that American Citizen Services would only run on an “emergency basis”.
Heather Nauert, spokeswoman for the US State Department, described the events that unfolded as a “small explosion” and that the embassy is conducting an “internal review” of the situation.
(2 of 2) Most probably, the device was a hand grenade. Police investigation and identification is under way directed by the prosecutor.— Govt. of Montenegro (@MeGovernment) February 22, 2018
Police Administration of Montenegro
The Montenegro government said in a statement on Twitter: “An unknown person committed suicide with an explosive device. Immediately before, that person threw an explosive device from the intersection near the Sport Centre into the US Embassy compound.
“Most probably, the device was a hand grenade. Police investigation and identification is under way directed by the prosecutor.”
Additional reporting from Associated Press.