Security forces of Libya's U.N.-backed government on Monday stormed the headquarters of the country's national oil company in the capital Tripoli shortly after gunmen had gone into the building, shooting randomly, setting off explosions and taking hostages, officials said.

At least one explosion rocked the building soon after the gunmen went in, starting a fire that swiftly spread through the lower floors, according to the officials.

The head of the company, Mustafa Sanallah, told a Libyan television channel that explosions and an exchange of gunfire between the attackers and the building's security guards have caused an unspecified number of deaths and injuries.

Health official Malek Merset said at least one body has so far been found inside the building and that there were dozens of injuries caused by the gunfire, smoke inhalation or explosions.

"The building was heavily damaged due to the fire. Smoke is everywhere," Sanallah said. "The gunmen attacked the lower floors with random shooting and explosions. It's a very violent attack."

There was no word on the fate of the gunmen, described by Libyan officials as "dark skinned terrorists," or whether they were still holding hostages.

Earlier, the Interior Minister of the U.N.-backed government, Brig. Gen. Abdul-Salam Ashour, said the attack was carried out by six gunmen and that employees were inside the building when it took place.

Monday's attack followed recent fighting in Tripoli between rival armed groups, which left at least 61 people dead. A cease-fire has been in place since last week.

 

Libya slid into chaos after the 2011 uprising that overthrew dictator Muammar Gaddafi and led to his death. It is now governed by rival authorities in Tripoli and the country's east.