CAIRO (AP) — An Islamic State affiliate in eastern Libya claimed responsibility for a suicide truck bomb attack targeting a police base in the town of Zliten that authorities said killed at least 60 policemen and wounded around 200.

In a statement posted on the Twitter accounts of IS sympathizers several hours after Thursday's attack, the group calling itself the IS Barqa Province said it was carried out by Abu al-Abbas al-Muhajir, who detonated his explosive-laden truck among the Libyan border police at the base.

The last name, al-Muhajir, implies that the attacker was not Libyan.

Earlier on Thursday, the IS-affiliated Aamaq News Agency also claimed the attack was carried out by the extremist group's Barqa Province affiliate.

The U.N. Security Council late Friday strongly condemned "the terrorist attack" in Zliten. It also condemned recent attacks on Libya's oil infrastructure by a group claiming allegiance to IS.

Libya slid into chaos following the 2011 toppling and killing of longtime dictator Moammar Gadhafi. The oil-rich country is torn between an Islamist government based in the capital, Tripoli, and a rival, internationally recognized administration in the east. Meanwhile, a U.N.-supported unity government sits in neighboring Tunisia.

The Security Council urged all parties "to join efforts to combat the threat posed by transnational terrorist groups exploiting Libya for their own agenda" by supporting the unity government.