The United Nations is looking into reports of looting and destruction of property in two towns outside Tripoli retaken by the forces of Libya's internationally recognized government, it said on Sunday.

"Reports of the discovery of a number of corpses at the hospital in Tarhouna are deeply disturbing," UNSMIL said in a statement, without blaming anyone.

"We have also received numerous reports of the looting and destruction of public and private property in Tarhouna and Alasabaa, which in some cases appear to be acts of retribution and revenge that risk further fraying Libya’s social fabric."

Alasabaa is another town south of Tripoli that was retaken by the GNA after changing hands several times.

"The GNA should take urgent steps to stop revenge crimes in Tarhouna," said Hanan Salah, a senior researcher at Human Rights Watch.

A spokesman for the GNA interior ministry sent Reuters a statement warning its forces that any reprisals in recaptured areas would be punished.

The Tripoli-based justice ministry said the GNA forces that entered Tarhouna had discovered more than 100 bodies in a morgue.

Jalel Harchaoui, research fellow at the Clingendael Institute, said international diplomatic efforts that had supported the Tripoli government "will be predicated on that government providing security, imposing order and promoting robust transitional justice".

(With input from agencies)