Another ship, the Alakrana, was recently captured in the Indian Ocean
Somali pirates have seized a Singapore-flagged container ship in the Indian Ocean, a maritime official says.
The MV Kota Wajar was headed to the Kenyan port of Mombasa when it was commandeered 300 nautical miles north of Seychelles.
Twenty one crew are on board the 24,637-tonne container ship, said an official from the East African Seafarers' Assistance Programme.
At least five vessels are now in the hands of Somali pirates, officials say.
The maritime security centre of the European Union, which has a patrolling anti-piracy naval force, confirmed the most recent attack.
The EU said in a statement that it had sent a patrol aircraft to investigate, but did not provide further details.
Pirate attacks around the world more than doubled to 240 during the first six months of 2009 compared with the same period in 2008, the ICC International Maritime Bureau's Piracy Reporting Centre said in July.
The rise in overall maritime hijacking is largely due to the increase in Somali pirate activity.