BAGHDAD, Aug 3: Guerillas launched a wave of attacks in Iraq on Tuesday, killing six national guardsmen in a suicide car bombing and four US soldiers in separate incidents in Baghdad and the volatile west of the country.

A roadside bomb also killed a local police chief in the capital, just hours before interim Prime Minister Iyad Allawi returned from a 10-day foreign trip during which he tried to win neighbouring countries' support in stabilizing Iraq.

The suicide car bomb blast at a checkpoint outside the town of Baquba wounded six other Iraqi guardsmen, said National Guard's Lt Mohamed al Dulaimi at the scene.

Baquba, 65kms north of Baghdad, has been the scene of numerous guerilla strikes in recent months, including a suicide car bomb last week that killed 70 people, many of them young men lining up to join the police force.

The US military said two American soldiers were killed in a roadside bomb blast on Baghdad's western outskirts. And two US marines were killed in action in the Anbar province in the country's west.

The four deaths raise to 681 the number of American troops killed in action since the occupation of Iraq. Besides attacking US soldiers, guerillas often target Iraq's fledgling security forces, accusing them of collaborating with some 160,000 foreign troops in the country.

Early on Tuesday, a roadside bomb in Baghdad's upscale Mansour district killed the head of a local police station and wounded three of his bodyguards. Guerillas have assassinated a number of senior officials as part of efforts to destabilize Mr Allawi's 36-day-old government.

REGIONAL SUPPORT: During his regional tour, Mr Allawi focused on tightening borders to stop foreign fighters entering Iraq and on drumming up support for more troops to help quell the resistance.

He called the trip a success and said he hoped countries including Pakistan and Bahrain might soon send forces. One of Mr Allawi's most pressing security challenges is a spiralling hostage crisis, which has forced the Philippines to withdraw troops and prompted at least two foreign firms to pull out of Iraq after their employees were threatened with death.

Talks to free seven foreign truck drivers threatened with execution have stalled since Monday, mediators said. The three Indians, three Kenyans and an Egyptian were seized last month.

A tribal sheikh trying to win their release said on Tuesday he was waiting to hear from the kidnappers, who have demanded their Kuwaiti employer leave Iraq and compensate families who suffered in US airstrikes on Fallujah. "Negotiations are still stopped at the moment. I have no idea on the fate of the hostages," Hisham al Dulaymi said.

TURKS TO PULL OUT: There has been a surge in kidnappings since Manila pulled its troops out last month to save the life of a Filipino driver. Some of the kidnappings have been carried out by groups linked to Al Qaeda ally Abu Musab al Zarqawi, who has claimed responsibility for some of the biggest suicide attacks in Iraq and the killing of several foreign hostages.

Websites showed militants loyal to Zarqawi shooting dead a Turkish captive on Monday. In response to the killing and the kidnappings of Turkish drivers, a Turkish truckers' group said it would stop transporting goods to US forces.

But other groups said they would not follow suit, saying trucking goods into Iraq was keeping Turkish families alive. "It is not possible for us to give up transporting goods to Iraq unless a war broke out between Turkey and Iraq," said Saffet Ulusoy, head of one of Turkey's main haulier groups.

"This is a route on which 50,000 Turkish families depend." Al Jazeera television said on Monday a Somali held by militants linked to Zarqawi would be freed after his Kuwaiti employer agreed to halt operations in Iraq. However, there has been no word on his fate since.

Scores of hostages from two dozen countries have been seized in the last four months. Most have been freed but several have been executed - at least four by beheading. -Reuters