The sustained bloodshed came after nearly 200 people were killed over the weekend, mostly in the war-torn capital.

Iraqi forces on Monday stepped up security in some volatile districts on the eastern side of the Tigris river, which runs through Baghdad, an AFP photographer reported.

Iraqi soldiers and National Guard police were deployed on Baghdad's main eastern highway leading to the Shia bastion of Sadr City, a repeated insurgent target, he said.

Tanks and other armoured vehicles along with National Guard police were seen at various locations on the road to Sadr City and in districts such as Karrada.

New control points were set up in the districts of Karrada, Rusafa, Mustansiriyah, Adhamiyah and Sadr City, all to the east of the Tigris.

On some bridges, guard posts were protected by tanks and barbed wire as soldiers stopped and checked drivers, the photographer said.

Thirteen bridges cross the Tigris river in Baghdad, but several have been sealed off to traffic.

Access to Sadr City itself was controlled by a barrier manned by army soldiers and police commandos.

Sadr City is the stronghold of the Mahdi Army, a Shia militia accused by the US military of leading the killing of Sunni Arabs in the chronic sectarian conflict in the capital.

It was not clear however if the new measures were part of a long-awaited security crackdown.

A senior Iraqi official, on condition of anonymity, said the security plan would be launched "in the next few days" after "the necessary security preparations have been completed".

The US military also declined to be specific.

"We continue to do operations as part of the plan in support of the (Iraqi) prime minister's goals to secure Baghdad," said spokesman Lieutenant Colonel Christopher Garver. "Operations have been going on."

Garver said US military troop movement was continuing as per the needs of the plan. "We are in the process of moving troops here as announced by our president," he told AFP.

On January 10, US President George W. Bush announced he would dispatch 21,500 troop reinforcements to Iraq, of which 17,500 are to be deployed in Baghdad as part of the new strategy.

One brigade of nearly 3,200 US troops has already arrived and is being deployed around the city.

A combat outpost dubbed "Casino" has been operating in the central Ghazaliyah district for around two weeks, the first of a string of such outposts to be jointly manned by Iraqi and US troops.

But Bush's plan is facing stiff opposition from opposition Democrats with a debate set on the floor of the Senate later Monday on a non-binding resolution rebuking the strategy.

Insurgents, meanwhile, launched brutal attacks killing at least 30 people in Iraq, with almost all of the violence in Baghdad.

A suicide bomber blew up his truck near a petrol station in southwest Baghdad's Al-Saidiyah district, killing at least 10 people and wounding 60 others, a security official said.

The truck loaded with wheat and a bomb exploded next to people lining up to buy petrol at the outlet, and a car bomb blew up near a children's hospital in Al-Sinaa, eastern Baghdad, killing four people and wounding 14.

Sixteen more were killed in other attacks.

Insurgents killed a US soldier northeast of Baghdad during combat operations, the military reported Monday.

The soldier died from wounds received during the attack on Sunday in the restive Diyala province.

A British soldier was killed Monday by a roadside bomb in southern Iraq, the Ministry of Defence (MoD) announced.

The bomb exploded near the US consulate in the main southern city of Basra, it added.

Insurgents have carried out a sustained bombing campaign that killed 200 people over the weekend.

The worst bomb attack was on Saturday when 130 people were killed in a central Baghdad Shia district when a suicide bomber blew up his explosive-packed truck in the Sadiriya market.

On Monday, the US and British militaries announced the deaths of three of their troops in Iraq, including a Briton.