BAQOUBA, Iraq - The insurgent group of Jordanian militant Abu Musab al-Zarqawi kidnapped a Somali truck driver in Iraq and threatened to behead him if his Kuwaiti company doesn't stop working there, according to a videotape aired today.

Iraqi health officials, meanwhile, raised the death toll by two to 70 from a suicide car bomb that devastated a busy, shop-filled street in Baqouba. Casualties from the vehicle-born bomb blast, which targeted Iraqi men waiting outside a police station to apply to join the police, overwhelmed Baqouba's hospital.

The blast is one of the deadliest single-bomb attacks since Saddam Hussein's fall more than a year ago.

Word came today that a national conference to choose an interim assembly - considered a crucial step toward establishing democracy - has been postponed.

The videotape of the Somali, released by the Tawhid and Jihad group, was aired by pan-Arab TV station Al-Jazeera and showed three masked and armed militants standing behind a seated man waving a passport. Al-Jazeera's news presenter identified the hostage as Ali Ahmed Moussa and said the militants had threatened to behead their captive in 48 hours if the Kuwaiti company he works for doesn't meet its demands.

Tawhid and Jihad has claimed responsibility before for a number of bloody attacks and beheadings of foreigners it has abducted, including U.S. businessman Nicholas Berg, South Korean translator Kim Sun-il and Bulgarian truck driver Georgi Lazov.

News of the latest hostage drama in Iraq followed Wednesday's announcement by another militant group that it had killed two Pakistani hostages it had recently kidnapped who had worked for the Kuwait-based al-Tamimi group.

In a videotape sent to Al-Jazeera on Wednesday, a group calling itself the Islamic Army in Iraq said they had carried out a threat to kill the Pakistanis because their country was discussing sending troops to Iraq. The newsreader said the video showed the corpses of the two men, but the station declined to show the footage.

"Those who have committed this crime have caused the greatest harm both to humanity and Islam," a statement from Pakistani President Gen. Pervez Musharraf said today.

Also today, the U.S. military said fighting between insurgents and American forces west of Baghdad killed two U.S. Marines.

The two Marines died in clashes Wednesday in Anbar province, the statement said. The U.S. military had initially said two coalition troops were killed during heavy fighting Wednesday in the Anbar city of Ramadi, but it had declined to reveal their nationalities.

Multiple U.S. military camps in Ramadi came under mortar attack Wednesday and two U.S. helicopters made emergency landings after coming attack from small arms before returning their base, the military said.

The deaths of the two Marines takes the tally of U.S. personnel killed in Iraq to at least 908 since the war began, according to an Associated Press tally.

The Polish Defense Ministry announced that one of its soldiers was killed and six were wounded in a separate attack. The Polish casualties came when the troops were hit by shrapnel from a booby trap set off by remote control, the ministry said.

Poland sent troops in support of the U.S.-led invasion of Iraq and now commands some 6,200 multinational troops in south-central Iraq from 16 countries, including 2,400 of its own.

The large number of civilian casualties in attacks has angered many and even raised questions on Islamic Web sites, where the morality of killing Muslims who work for U.S. coalition forces in Iraq has been debated.