Four in five Iraqis have little or no confidence in US-led forces and most think their presence is making security worse, but despite that only about a third want them to leave now, a poll showed yesterday.

Four years after the US-led invasion that toppled Saddam Hussein, insurgents kept up the pressure with bomb attacks in Kirkuk and Baghdad yesterday.

With Iraq bogged down in sectarian violence that threatens to tip the country into civil war, US President George W. Bush announced a strategy shift this year and is sending some 26,000 reinforcements for a security crackdown focused on Baghdad.

Bombers struck in the city of Kirkuk, to the north, yesterday, with two car bombs and four roadside bombs killing at least 12 people and wounding 39, police Brigadier Sarhat Qader said. Earlier police sources had put the toll at 18.

The city is a volatile mix of Shi'ites, Sunni Arabs, ethnic Kurds and Turkmen, and has seen growing sectarian violence.

A bomb in a bag near a Shi?ite mosque in central Baghdad killed four people and wounded 25 yesterday, police said.

With American public opinion turning increasingly against the Iraq war, a poll published by the BBC yesterday showed only 18 percent of Iraqis have confidence in US-led forces.

The poll of more than 2,000 people, commissioned by the BBC, ABC News, ARD and USA Today, indicated Iraqis have become less optimistic about the future compared to a similar survey in 2005 when respondents were generally hopeful, the BBC said.

Asked whether their lives were overall better or worse than before the invasion, 43 percent said better, 36 percent worse and the rest about the same. Expectations for how things will be in a year were much lower than in 2005, with only 35 percent expecting improvement compared to 64 percent in a 2005 survey.

The survey showed sharp geographical variations, with confidence in US-led forces highest in the north, at 46 percent, and non-existent in Baghdad, where 100 percent said they had not very much or no confidence in US-led forces.

Overall, 18 percent of Iraqis expressed confidence in US forces and 69 percent said their presence made security worse.

US and Iraqi forces launched a major crackdown in Baghdad in mid-February that commanders say has already halved civilian deaths, largely through a reduction in the number of victims of death squad killings blamed on militias.

In Baghdad, the poll showed 100 percent said US and other foreign forces had done a bad job in Iraq, opposed the presence of US-led forces and said the presence of US forces was making security in the country worse.

Despite that, only 35 percent of all Iraqis and 36 percent in Baghdad said US forces should leave now.

The most popular view on how long they should stay was ?until security is restored?, with 45 percent of Baghdad residents and 38 percent of all Iraqis picking that option.

Anti-war sentiment propelled Democrats into the majority in the US Congress last November and the fourth anniversary of the Iraq war this week was marked by anti-war protests around the United States over the weekend.

Defense Secretary Robert Gates said on Sunday it was too early to evaluate whether the latest US strategy was working but ?so far, so good?.

US generals say it will probably be summer before the impact of the extra troops can be fully assessed, and have warned the troop increase could have a ?squirting effect? where al Qaeda and insurgents would operate elsewhere, Gates said.

?With American public opinion turning increasingly against the Iraq war, a poll published by the BBC yesterday showed only 18 percent of Iraqis have confidence in US-led forces?

IRAQ VIOLENCE, IN FIGURES

■ Many thousands of people have died in the Iraq conflict since the US-led coalition invaded in March 2003. But establishing how many lives have been lost is a controversial topic, with most estimates varying wildly.

More than 3,400 soldiers from the coalition have died so far, but US forces do not keep complete records of civilians killed in the conflict. Nor does the Iraqi government have a precise figure, although estimates from the health ministry in November 2006 ranged from 100,000 to 150,000 dead.

This contrasts with a survey of Iraqi households published by the Lancet, which suggested that about 655,000 Iraqi deaths had occurred "as a consequence of the war", by July 2006.

These estimates are both higher than the running total of reported civilian deaths maintained by the campaign group, Iraq Body Count. Using two media reports as their source for each death, IBC say the civilian death toll is now more than 60,000, including more than 3,258 police, but also warn that many deaths may not have been reported.