Pirates off the coast of Somalia have attacked two vessels, and at least one of those has been captured.

The European Union's anti-piracy force says pirates hijacked a chemical tanker on Monday named the MV Theresa with 28 North Koreans on board.

In a second incident, pirates attacked a Ukrainian cargo ship. Cmdr. John Harbour, a spokesman for the EU force, says that private security guards on board fired on the pirates, wounding two. Harbour says the Ukrainian ship was not hijacked.

A Somali man who claims to be a spokesman for the pirates, Gedi Ali, told The Associated Press on Tuesday that pirates had captured the Ukrainian ship. Ali also says two pirates were wounded in the attack.