Somali pirates have hijacked an oil tanker off Yemen, marking a resurgence in piracy. A Somali maritime security official says six armed pirates seized the Eritrean-flagged M.T. Sibu 1 on Thursday. The tanker, managed by a UAE-based company, was sanctioned by the U.S. Treasury last year. It had 20 crew members aboard. This incident follows the hijacking of the Lutuf, a Cameroon-flagged vessel, three days earlier. The Sibu 1 is the sixth commercial vessel hijacked by Somali pirates since April. Puntland’s Security Ministry says forces beyond its control are behind the renewed piracy.