PODGORICA -- A Serbian-born assailant threw an explosive device at the U.S. Embassy in Montenegro before blowing himself up outside the compound in an attack in the middle of the night, authorities in the Balkan country said.

Prosecutors and police on February 22 identified the attacker as Dalibor Jaukovic, a former Yugoslav Army soldier who had expressed anti-NATO sentiments.

U.S. and Montenegrin officials said nobody at the embassy was injured in the attack in the capital, Podgorica, which the government said occurred at 12:30 a.m. on February 22.

U.S. State Department spokeswoman Heather Nauert said late on February 22 that the department doesn't believe the attack "is part of an ongoing threat" and that the embassy shut down its consular services for the day only "out of an abundance of caution."

Officials said the attacker, who was born in the Serbian city of Kraljevo in 1976, activated an M75 hand grenade, and that the U.S. Federal Bureau of Investigation (FBI) was involved in the investigation.

Police officials had told RFE/RL on condition of anonymity that the assailant had been living in Podgorica.

Photos posted on what appears to be his Facebook profile include an award that he won for service in the Yugoslav Army in 1999 that seems to be signed by the late Serbian strongman Slobodan Milosevic. There was no immediate official confirmation of his military past or awards.

Jaukovic wrote "No to NATO" in a May 2017 Facebook post.

Seventy-eight days of NATO air strikes against Serbia brought to an end the war in Kosovo in 1999, when Montenegro was still part of Yugoslavia.

Montenegro, the smallest former Yugoslav republic, became the 29th country to join the NATO military alliance in May 2017, a step that was bitterly criticized by Russia and opposed by some Montenegrins who advocate closer ties with Moscow.

Police said earlier that embassy officials "found a lifeless body across the street from the embassy, close to the Moraca River bank" after citizens reported an explosion.

The investigation indicated that the man was "killed after detonating an explosive device and after he threw an explosive device...into the embassy compound," a police statement said, adding that there was no damage other than a crater from the explosion.

Eyewitnesses saw the assailant throw an object over the wall of the embassy compound, according to Steve Goldstein, the U.S. State Department's undersecretary for public diplomacy and public affairs.

Goldstein said the man who set off the blast was killed but that there were no injuries among staff at the embassy, which was closed for the night, The New York Times reported.

The embassy building was not damaged and diplomatic security officials who swept the grounds found no other explosives, Goldstein said.

The spot where the government said the attacker was standing when he threw the device is close to the embassy compound but not within throwing distance of the main embassy building.

Interior Minister Mevludin Nuhodzic said that the ministry and government "strongly condemn the attack on the U.S. Embassy," expressing regret and saying he authorities were committed to "securing the full safety and security" of embassy staff.

In a tweet earlier, U.S. State Department spokeswoman Heather Nauert said that there was a "small explosion near the U.S. Embassy compound."

Goldstein said the State Department did not know what the motive for the assault was or whether it was meant to be a suicide attack.

Residents in the area heard two explosions, local media reported.

The embassy canceled all services on February 22 and issued a security alert warning U.S. citizens to stay away until further notice.

It also advised Americans to avoid large gatherings in the capital and monitor local media for updates on the situation.

The European Union is following the "developments on the ground," Maja Kocijancic, a spokeswoman for EU foreign-policy chief Federica Mogherini, told RFE/RL.

"Of course, violence is not something that we would condone, but we are waiting for the results of this investigation," Kocijancic said.

Montenegro, the smallest former Yugoslav republic, became the 29th country to join the NATO military alliance in May 2017, a step that was bitterly criticized by Russia and opposed by some Montenegrins who advocate closer ties with Moscow.

The attack came as Russian Foreign Minister Sergei Lavrov was in neighboring Serbia on a two-day visit to the country, which is juggling its close, warm ties with Moscow with an effort to join the European Union.

Russia and the United States have accused each other of stoking tension in the Balkans, a flashpont of animus between the two countries -- as well as some cooperation -- during the wars in the former Yugoslavia in the 1990s and in their wake.

The incident in Podgorica came exactly 10 years after demonstrators attacked the U.S. Embassy in Belgrade and set part of it on fire amid large protests over Kosovo's strongly U.S.-supported declaration of independence from Serbia.

There was no immediate indication of any link.

Montenegro became an independent state after a majority of its citizens voted in May 2006 to split with Serbia instead of maintaining a union with its larger neighbor.

The Adriatic coastal country of 640,000 is also seeking to join the EU, which has indicated that both Serbia and Montenegro may gain entry by 2025 if they fulfill conditions.

Montenegro has traditionally warm ties with Russia, but its relations with Moscow were strained by its accession to the Western military alliance.

The government has accused several Serbian and Russian citizens of plotting a coup in 2016 parliamentary elections, claiming they planned to assassinate the prime minister and install a pro-Russian leadership to halt Montenegro's bid to join NATO.

The Kremlin has denied claims that "Russian state bodies" were involved in the alleged plot.

With reporting by RFE/RL's Balkan Service, AP, Reuters, AFP, dpa, Portalanalitika.me, and The New York Times