More than two dozen Bulgarian soldiers are refusing deployment in Iraq, following the deaths of five countrymen in an attack in the Middle Eastern country, a senior military official said Friday.

Between 25 and 30 soldiers of the Second Bulgarian Contingent (search), due to leave for Iraq in early January to replace the troops there now, have decided not to go on the mission, said Gen. Nikolai Kolev, the army chief of staff. The withdrawals would not affect Bulgaria's mission in Iraq, he added.

All soldiers in Bulgaria's Iraqi missions have volunteered to take part.

Bulgaria (search), a staunch supporter of the U.S. military campaign in Iraq, last August sent a 485-soldier light infantry battalion to Iraq.

Some of the replacement soldiers changed their minds after five of their countrymen were killed a week ago in a blitz of four suicide car bombs, rocket-propelled grenades and mortars that blasted coalition military bases and the Iraqi governor's office.

The troops who withdrew will have to refund the costs of their training and medical examinations, Kolev said.

Government officials have said that Bulgaria will remain a firm member of the U.S.-lead coalition, despite the deaths.

"Keeping our military contingent in Iraq is a question of principle," Prime Minister Simeon Saxcoburggotski (search) said earlier this week.