Heavily armed Somali pirates have seized another Malaysian tanker in the latest such attack in the waters off the Horn of Africa country, a maritime official said on Saturday. “We believe it's a Malaysian bulk carrier and it was hijacked last night,” Andrew Mwangura, head of the Kenya-based East Africa Seafarers' Assistance Program told Reuters. In Kuala Lumpur, Malaysian national carrier MISC said its ship was the hijacked vessel. The tanker, Bunga Melati 5, was carrying 30,000 tons of petrochemicals and heading towards Singapore from Yanbu in Saudi Arabia It had 36 Malaysians and five Filipinos on board when it was hijacked in international waters off the coast of Yemen. “MT Bunga Melati 5 was sailing within the vicinity of the designated security corridor. The vessel attempted evasive manoeuvring before being overpowered by the hijackers,” it said. “The coalition (naval) forces within the vicinity were alerted but were unable to prevent the hijacking as safety of the crew onboard is of priority,” it said. Lawlessness is spreading fast onshore as Somalia collapses into the worst fighting for two nearly decades. That is fuelling a wave of piracy that increasingly threatens vessels using the Gulf of Aden, one of the world's most important waterways. Somali gunmen have hijacked at least 30 ships in the area so far this year. Last week, they seized four in 48 hours, and are now holding about 130 crew hostage on at least eight vessels from Malaysia, Thailand, Japan, Germany, Nigeria and Iran. The piracy is also hampering aid shipments to Somalia, worsening a humanitarian crisis, and the increase in attacks has forced Western navies to take action to protect shipping. Nearly 20,000 ships pass through the Gulf of Aden each year, heading to and from the Suez Canal.