“UNSMIL is deeply concerned about reports that one civilian was killed, three were injured and a number of other demonstrators were arrested on 12 September,” the organization's website said.
It is noted that the authorities used excessive force against peaceful demonstrations.
The organization also called for the release of all those arbitrarily detained and arrested.
Earlier, the interim Libyan government, sitting in the east of the country, submitted a letter of resignation to the House of Representatives (parliament).