BAGHDAD, Iraq — Insurgents launched a string of attacks Wednesday in the northern city of Mosul as part of their escalating campaign of violence before the Jan. 30 elections, killing two Iraqi National Guardsmen and wounding two others in a car bombing.

A U.S. soldier assigned to the 1st Marine Expeditionary Force was killed in action in the volatile western Anbar province, the military said Wednesday. The unit is based at Camp Fallujah west of Baghdad.

In Baghdad, U.S. forces detained six suspects in the slaying of the provincial governor of the area around the Iraqi capital. Gunmen opened fire on Ali al-Haidari's three-vehicle convoy Jan. 4, killing the governor and six bodyguards.

Two of those detained were directly involved in the slaying, said Brig.-Gen. Jeffery Hammond, assistant commander of the 1st Cavalry Division, which controls Baghdad.

Iraq's insurgents have repeatedly targeted government officials around the country, saying they are allies of the U.S.-led coalition.

On Tuesday, insurgents in Mosul hit a convoy of American and Iraqi forces by detonating a roadside bomb and firing from a mosque, killing three National Guardsmen.

The troops were bringing heaters and other supplies to a school when they were attacked, a military statement said. The convoy was hit first with a roadside bomb and then sprayed with gunfire from a nearby mosque. No Americans were reported hurt.

In a separate clash, insurgents fired on a U.S. patrol in southern Mosul, sparking a battle that killed one attacker and injured another.

In the city of Baqoubah, northeast of Baghdad, gunmen shot dead Jawad Ibrahim, an assistant to the mayor, as he was fixing his car in an industrial neighbourhood, police said.

On Tuesday, Prime Minister Ayad Allawi acknowledged that parts of Iraq probably would not be safe enough for people to vote in the Jan. 30 elections, and he said he plans to boost the size of the country's army to 150,000 men from 100,000 by year's end.

Allawi discussed preparations for the election with U.S. President George W. Bush by phone on Tuesday, and both leaders underscored the importance of going ahead with the vote as scheduled, White House spokesman Scott McClellan said.

Also Tuesday, gunmen stopped three trucks carrying new Iraqi coins south of Baghdad and killed the drivers, stole the money and set the trucks on fire, a police official said.

The attack occurred near the town of Salman Pak, about 20 kilometres southeast of Baghdad. The trucks were carrying the money from the southern port city of Basra to the Central Bank of Iraq in Baghdad.

The Central Bank announced Jan. 1 it would start circulating coins for the first time since Saddam Hussein's regime abolished them in the aftermath of the 1990 Gulf War. Coins were scrapped in 1991, when the international embargo sent Iraq's annual inflation rate soaring upward of 1,000 per cent.

The military had no further details about the circumstances of the American's soldier's death Tuesday, which brought to 1,356 the number of American troops killed in Iraq since the invasion in March 2003. At least 1,069 died as a result of hostile action, the Defence Department said. The figures include three military civilians.

Also Wednesday, a U.S. military official involved with reconstruction projects briefed reporters on the progress in repairing and building new water and sewage treatment plants, power stations and upgrading oil infrastructure.

Brig.-Gen. Thomas Bostick, commander of the Gulf Region Division of the U.S. Army Corps of Engineers, said $4 billion has been spent so far on 1,550 projects that also include work on schools, clinics and railway stations.