Oil depots again catch fire amid fighting over airport in Libya's capital after being put out

In this handout photo provided by the Hellenic Navy, a navy special operations team inspects waters as a plume of smoke is seen over Libya's capital Tripoli on Thursday, July 31, 2014. A Greek frigate was was used to evacuate Greek embassy staff and others from Tripoli. The navy said 186 people, including the Embassy staff, other Greek nationals and citizens from China, Britain, Belgium, Russia and Albania were being transported to a port near Athens. With the violence in Libya escalating to its worst level since the 2011 ouster of dictator Moammar Gadhafi, governments from around the world are scrambling to evacuate their citizens from the country, many seeking help from nearby Greece.(AP Photo/Hellenic Navy) (The Associated Press)

A man stands on the rubble of the main building of the security headquarters that was collapsed after an attack by Islamic hard-line militias in Benghazi, Libya, Friday, Aug. 1, 2014. Islamic hard-line militias, including the group accused by the United States in a 2012 attack that killed the ambassador and three other Americans, claimed control of Libya's second largest city, Benghazi, after overrunning army barracks and seizing heavy weapons. (AP Photo) (The Associated Press)

A security office building is damaged after an attack by Islamic hard-line militias in Benghazi, Libya, Friday, Aug. 1, 2014. Islamic hard-line militias, including the group accused by the United States in a 2012 attack that killed the ambassador and three other Americans, claimed control of Libya's second largest city, Benghazi, after overrunning army barracks and seizing heavy weapons. (AP Photo) (The Associated Press)

An official and witnesses in Libya's capital say random shells fired by rival militias fighting for control of its international airport hit oil depots, setting them ablaze after a massive fire last month.

The weekslong violence in Tripoli and in Libya's second-largest city of Benghazi have killed more than 200 people and wounded almost 900. The violence has forced diplomats to flee and close their embassies while foreign nationals and Libyan citizens streamed into neighboring Tunisia searching for safety.

A Libyan official at the National Safety Agency, who spoke on condition of anonymity because he was not authorized to speak to journalists, said the oil depots caught fire Saturday after three others caught fire last month.

Tunisia also opened its main border crossing with Libya after brief closure Friday.