The US said yesterday it had sent combat troop reinforcements into Iraq, dashing hopes of a substantial withdrawal, as American commanders scrambled to contain a wave of violence and help the new Iraqi government assert control.

About 1,500 soldiers from a reserve force based in Kuwait were deployed in Anbar province, an insurgent stronghold stretching from Baghdad to the Syrian border. The deployment was described officially as "short-term". Military officials quoted anonymously yesterday said it should last no more than four months, but it was a blow to the Bush administration's hopes of bringing troops home after the formation of the new government in Baghdad. There were about 130,000 US troops in Iraq before the deployment and that figure is unlikely to change for several months, military officials said.

"The situation in al-Anbar province is currently a challenge but is not representative of the overall security situation in Iraq, which continues to improve as the Iraqi security forces increasingly take the lead," Lieutenant Colonel Michelle Martin-Hing said yesterday.

But the bloodshed nationwide showed no sign of abating yesterday when bomb attacks killed at least 46 people, wounding dozens more.

A car bomb exploded at a market in Husseiniyah, a Shia neighbourhood north of Baghdad, killing 25, and 12 more were killed when a car packed with explosives detonated at a car sales centre in Hillah, 60 miles south of the capital. A bomb left in a plastic bag in a Baghdad bakery blew up, killing nine.

The new Iraqi prime minister, Nuri al-Maliki, held talks yesterday in an attempt to forge an agreement on who should serve as defence and interior ministers in his government. More than a week since the government took office and nearly six months since elections, Iraqi parties cannot agree on the two crucial portfolios.

Mr Maliki faces huge challenges. He demanded "answers" from US commanders on civilian deaths at the hands of their troops, after news emerged that an official report would find that American marines killed 24 civilians in cold blood in the town of Haditha last November.

Alarmed by the increasing turmoil in Basra, he is set to head south today in a bid to wrest Iraq's increasingly restive second city from the clutches of warring Shia factions and oil smuggling gangs.

"We must restore security in Basra and if any defy peaceful solutions then force will be the solution," he told Reuters. "There's no way we can leave Basra, the gateway to Iraq, our imports and exports, at the mercy of criminal, terrorist gangs. We will use force against these gangs."

Officials said they hoped Mr Maliki's visit would help calm tensions. Predominantly Shia Basra has largely escaped the violence of more mixed cities such as Baghdad. But the last year has seen a rapid deterioration in security as competing Shia factions vie for control and influence.

The main rivals are the armed Badr organisation, which is close to the Supreme Council for Islamic Revolution in Iraq, led by militant Shia cleric Moqtada al-Sadr, and the smaller Fadhila party, whose power base is in Basra. They blame each other for corruption and organised crime and for controlling militias which have infiltrated police units.

The rivalry worsened earlier this month when the governor of Basra province, a member of Fadhila, demanded the dismissal of the city's police chief. Basra residents, meanwhile, criticise the British forces there for allowing the city to slip steadily out of control. Mr Maliki said: "I will go tomorrow with a delegation from the government and from the parliament. We will spare nothing to find a solution."

At the weekend, officials from Fadhila, which controls the governorship of Basra province, said it could halt oil exports to win concessions from Baghdad. During talks to form the government, the party demanded control of the oil ministry.

The post went to Hussein Sharistani, the former nuclear scientist with close ties to Ayatollah Sistani, who took office vowing to stamp out corruption in the country's oil sector. Basra dominates the drilling and export of the majority of Iraq's oil. But oil officials estimate that smugglers, some of whom are linked to the Shia militias, are siphoning millions of dollars a week of much-needed reconstruction revenues.

Backstory

Iraq has taken more troops to occupy than to invade. About 100,000 US soldiers and marines (alongside 26,000 British troops) entered in March 2003; neo-cons in Washington who pushed for the war assumed most would be home by the end of 2003. More than three years on, there are 130,000 US and 7,200 British troops in the country, and the insurgency shows no sign of waning after December's elections and last week's new government. However, the US is down from a peak of 150,000 troops in January last year.

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