Somali pirates hijacked the oil products tanker M.T. Sibu 1 off Yemen, marking the latest in a resurgence of piracy across the Gulf of Aden and western Indian Ocean.

Six armed pirates seized the tanker Thursday and reportedly took it toward Somalia’s Puntland coast, with 20 crew members aboard.

The Sibu 1 is managed by a UAE-based company and was previously sanctioned by the U.S. for allegedly belonging to an Iranian “shadow fleet” used to evade sanctions.

The hijacking was the sixth commercial vessel seized by Somali pirates since April, with attacks increasingly occurring farther from Somalia’s coastline, the AP has reported.

International authorities have recorded a rise in piracy and hostage-taking, while Puntland officials have blamed unidentified outside forces for the renewed attacks and raised concerns about airstrikes near coastal communities.