United Nations Secretary-General Kofi Annan on Friday called for the release of two Bulgarians and one Filipino who are reportedly held hostage by anti-American militants in Iraq.

A statement issued by a United Nations spokesman said Annan "is deeply concerned about the threats to the lives" of the three kidnapees.

"The secretary-general calls for the release of these three persons and all other innocent civilians who may have been abducted for political ends in the conflict," said the statement.

On Friday, a group linked to the al-Qaida terrorist network said it would execute two Bulgarian drivers, who were kidnapped on Thursday, if US troops refuse to release all Iraqi prisoners within 24 hours.

Bulgaria has become the latest country to be mired in a wave of hostage taking incidents in Iraq in recent months.

Meanwhile, kidnappers have given the Philippine government until Sunday to withdraw its troops from Iraq or they will kill a Philippine driver abducted earlier this week.

(Xinhua News Agency July 10, 2004)