One of Libya’s most wanted human traffickers was killed Sunday in the capital, Tripoli, Libyan officials said, fueling tension in the western part of the North African country, Azernews reports, citing ABC news.

Abdel-Rahman Milad, who commanded a coast guard unit in the western town of Zawiya and was sanctioned by the United Nations Security Council, was shot dead by unknown assailants, the officials said.

The circumstances of his death were not immediately known, and no group claimed responsibility for his killing.

Libyan media outlets reported that he was shot while he was in his vehicle in the Sayyad area, in the western part of Tripoli. Footage circulated online showed a white Toyota Land Cruiser for Milad with bullet marks on its side.

Both officials spoke on condition of anonymity for their safety. There was no comment from the Tripoli-based government of Prime Minister Abdul Hamid Dbeibah.