MORTAR barrages hammered the heavily fortified Green Zone and elsewhere in central Baghdad today, killing at least one person and underscoring the vulnerability of even Iraq's best-protected areas ahead of national elections.

Also today, a car bomb exploded next to a Bradley fighting vehicle near Beiji, about 250km north of Baghdad, wounding two US soldiers and two Iraqi National Guardsmen.

US President George W. Bush insisted that crucial elections set for January 30 must not be delayed, rejecting calls from more than a dozen political parties there to postpone them until security at the polls can be ensured.

"It's time for Iraqi citizens to go to the polls," Mr Bush told reporters in the Oval Office today.

The Pentagon has said US troop strength in Iraq will be raised from 138,000 to about 150,000 by mid-January - the highest level of the war - in order to provide security for the election.

The Iraqi Islamic party, a Sunni political group, said it would push forward with demands to postpone the elections and would hold a conference on Sunday in a bid to muster more support for the call.

"We're trying to create a force to pressure the (electoral) commission and the government to postpone the elections," party official Ammar Wajeeh said. "We will do our best and we will continue this process until the very end."

"We are not convinced that elections could be held on this date so long as the security situation remains the way it is," Mr Wajeeh said.

The calls for delay also have been strongly opposed by Shiite politicians and the influential Shiite religious authority.

Shiites comprise about 60 per cent of Iraq's nearly 26 million people and have been eagerly awaiting elections to transform their numbers into the political power they were deprived of under Saddam Hussein.

In Baghdad, at least five mortar rounds exploded today, including two in Baghdad's Green Zone, the compound that holds Iraq's interim administration and foreign diplomatic missions.

One round struck near a mobile phone office in Baghdad's Arasat neighbourhood, killing one person and wounding three, police Lieutenant Muhsin Khazim said. Witnesses also said people were wounded in the other blasts around Baghdad, but the number of casualties wasn't known.

Last week, a mortar attack killed four Nepalese employees of a British security firm and wounded at least 12 in the Green Zone.

In the northern city of Mosul, 10 insurgents were killed in a clash with Iraqi security forces, an Iraqi general said today.

Major General Rasheed Feleih said two rebels were captured during the firefight, which flared overnight when a police special forces unit was conducting a sweep through the city's troubled Islah neighbourhood.

Mosul's 5000-member police force disintegrated during an insurgent uprising last month, forcing the US command and the interim government to divert troops from their offensive in Fallujah.

In the town of Baladruz, about 80km northeast of Baghdad, attackers gunned down a police colonel as he walked through a market, according to a policeman there, Ahmed Hassan. Insurgents repeatedly have targeted Iraqi police, who are cooperating with US forces.

The US Embassy also banned its employees from using the highway linking Baghdad to the international airport, regarded as one of the country's most dangerous roads.

"Until further notice, no mission personnel will be permitted to use the main road from the international (Green) zone to the Baghdad International Airport for security reasons," a warden's message said.

The 15km stretch of road has been the scene of repeated roadside bomb and suicide attacks generally targeting US military personnel and civilian contractors working on reconstruction projects in Iraq.

Insurgents have steadily stepped up attacks in Iraq, particularly in Baghdad, ahead of the scheduled elections.

The embassy statement also cautioned US citizens in Iraq to review their security and warned those planning to travel to Iraq to consider whether such a trip was "absolutely necessary."

On Monday, the British Foreign Office issued a similar warning ordering its staff from travelling on the airport road for security reasons.

The latest attack on the road occurred on Wednesday, when three people were injured after a car bomber detonated his vehicle as several SUVs, favoured by US and other Western security contractors, were passing by.

The US military said a vehicle accident in western Baghdad on Wednesday killed one US soldier and injured four. It was the first reported US military death in Iraq for December, and brought the number of American deaths since the beginning of the Iraq war in March 2003 to 1257, according to an Associated Press count.

On The Net

www.news.com.au