BEIRUT (AP) — Two weeks after clashes between armed factions in Lebanon's largest Palestinian refugee camp ended, militants are still occupying a United Nations-run school complex, U.N. officials said Thursday.

Dorothee Klaus, director of the U.N. agency for Palestinian refugees, or UNRWA, in Lebanon, said in a statement that the agency has “received alarming reports that armed actors continue to occupy its installations including a school compound" in the Ein el-Hilweh camp.

The compound provides education to 3,200 out of a total of 6,000 students in the camp, which is home to more than 50,000 people. Earlier this month, Klaus said that the start of the school year might be delayed for students in the camp due to damages to the school facilities.

Klaus said the continued presence of militants is a “grave violation of the inviolability of UN premises under international law, which compromises the neutrality of UNRWA installations and undermines the safety and security of our staff” and of the refugees living in the camp.

A local Palestinian official, who spoke on condition of anonymity because he was not authorized to speak to the media, said militants from both of the opposing sides had taken over different schools, using them as a “safe haven," and had looted computers and equipment.

The school buildings had been heavily fortified to protect children in the event of clashes, after previous outbreaks of fighting in the camp.

Several days of heavy street battles broke out between the Fatah movement of Palestinian President Mahmoud Abbas and the Islamist groups Jund al Sham and Shabab al Muslim after Fatah accused the Islamists of gunning down a Fatah military general, Abu Ashraf al Armoushi, in the camp on July 30.

The fighting killed at least 13 people, injured dozens more and caused millions of dollars of damages in the camp, according to UNRWA officials.