A foreign aircraft likely belonging to the United Arab Emirates or Egypt was responsible for an airstrike on a Libyan migrant centre that killed more than fifty people, a United Nations report has found.

A report drawn up by the United Nations Security Council’s expert group on Libya concluded that the July 2 rocket attack on the Tajoura holding centre in Tripoli, which killed 53 and left 130 injured, was likely carried out by a Mirage 2000-9 fighter jet, diplomatic sources told The Daily Telegraph.

The Libyan National Army, the faction that is besieging Tripoli, does not operate such aircraft, but they are flown by the air forces of its principal backers, Egypt and the United Arab Emirates.

The finding comes in a highly critical report into violations of UN Security Council Resolutions on Libya which accuses the UAE, as well as Jordan, and Turkey, of fuelling the conflict in Libya by flouting an arms embargo.

The three countries have “routinely and blatantly” supplied weapons to the warring parties “with little effort to disguise the source,” says the report, which is to be published in mid-December and was submitted to members of the Security Council this week.