The boat was towed to Somali coast, the September website reported on Friday.The hijacking came as pirates have recently stepped up their attacks off Yemen hijacking some Yemeni and foreign ships and tankers.A Russian oil tanker that had been hijacked off Yemen coast last week was released by a Russian warship of those patrolling the region on anti-piracy mission.Reports surfaced that the captain of the tanker could contact the warship after pirates boarded the tanker and fired at it.The tanker was seized after it left Bashyer Port en route for China, independent sources told Yemen Post.A crew of 23 members was onboard when the hijacking took place about 350 nautical miles of Yemen's southern coast.The cost of the oil aboard the tanker was estimated at $ 52 million.Prior to the hijacking, pirates took over a Yemeni cargo ship after it sailed from Mukalla port en route to Aden.It was carrying various products and a crew of 9 Yemeni sailors was onboard.Sources said that information had surfaced that the ship was seen at Somali Qarta'a port.An effort was underway to release.In recent weeks, a number of Yemeni and foreign ships escaped pirate attacks in the pirate-plagued Gulf of Aden.All attacks and attempts took place though the first quarter of this year saw less pirate activity.