Armed men stormed the headquarters of Libya's National Oil Company in Tripoli, engaging guards in a deadly gun battle with at least one large blast going off in an apparent suicide attack.
At least two of the company's staff were killed and 10 wounded, the health ministry said. Two gunmen also died in the attack on Monday when security forces fought to regain control of the key building in the centre of the Libyan capital.
"The security services are looking for gunmen in the building, but our priority is to evacuate the civilians stuck inside," said Ahmed Ben Salem, a spokesman for the Deterrence Force, a militia that operates as Tripoli's police force.
"The situation is under control," he added.
'Number of hostages'
According to the interior ministry, the bodies of at least two attackers were found inside the NOC's headquarters.
"A total of six perpetrators appear to have attacked the building where they took a number of hostages," Interior Minister Abdulsalam Ashour was quoted as saying by Al-Ahrar television channel.
The Deterrence Force described the incident as a "terrorist" attack and posted photos on its Facebook page that it said showed remains of suicide bombers.
An explosion rocked the building soon after the attackers went in, starting a fire that swiftly spread through the lower floors.
No group claimed the attack so far. But the interior ministry said in a statement initial indications showed the gunmen were affiliated with Islamic State of Iraq and the Levant (ISIL, known as ISIS).
It was the first attack of its kind against the top managers of Libya's state oil industry. Armed groups regularly block oilfields to make demands, but the NOC headquarters had so far been spared the violence.
Security forces smashed windows so staff could escape and several people were hurt by shattered glass.
"The building was heavily damaged due to the fire. Smoke is everywhere," the head of the company, Mustafa Sanallah, told a Libyan television channel.
"The gunmen attacked the lower floors with random shooting and explosions. It's a very violent attack."
Sanallah confirmed to the Libya 218 news channel that staff members had been killed and others wounded, some of whom were in "serious condition".
An NOC staff member, who said he jumped out of a window to flee, told the Reuters news agency on condition of anonymity "several people were shot" during the attack.
Al Jazeera's Mahmoud Abdelwahed, reporting from Tripoli, said there was a "state of panic" following the brazen assault.
"The masked men were armed with automatic rifles when they stormed the main gate of the building. They shot at the security guards and used hand grenades," he said, citing security officials.
Monday's attack came less than a week after a fragile truce suspended fierce clashes between rival armed groups in Tripoli. Days of fighting in the capital left at least 63 people dead.
Libya has remained dogged by turmoil since 2011, when a bloody NATO-backed uprising led to the overthrow and grisly death of long-serving leader Muammar Gaddafi after more than four decades in power.
Since then, Libya's stark political divisions have yielded two rival seats of power - one in Tobruk and another in Tripoli - and a host of heavily armed groups.
In May, fighters affiliated with ISIL claimed responsibility a deadly attack on the national election commission offices in Tripoli. It also said it was behind an attack in 2015 on the Corinthia hotel, a landmark location in the capital.
ISIL overran Sirte, 600km east of Tripoli, in 2015. The group was pushed out by government forces and allied militias in December 2016 but has continued to carry out attacks.
The National Oil Company provides the vast bulk of Libya's state income and, along with the Tripoli-based central bank, is one of the only state institutions still functioning well amid widespread chaos.
|Ambulances and security vehicles near the headquarters of the National Oil Company in the Libyan capital [Hani Amara/Reuters]|