BAGHDAD, 24 June 2005 — Four car bombs shook Baghdad after dawn yesterday, killing at least 17 people and wounding dozens in the second wave of attacks within hours, police said.

The previous evening car bombs in a mainly Shiite district of the city killed 18 people, after a day of talks in Brussels between the new Shiite-led government, its US backers and other nations. Guerrillas claimed responsibility.

In Washington, US Defense Secretary Donald Rumsfeld rejected a call in the Senate to consider setting a timetable for a withdrawal of US forces from Iraq, saying it would “throw a lifeline to terrorists”.

But statements by US officials that the Sunni insurgency is fading have been met with skepticism from some lawmakers

Despite a month-long crackdown by US and Iraqi troops and police in Baghdad, Al-Qaeda allies and other militants have mounted major attacks on three days this week, while lower level violence is keeping up pressure on all security forces.

Police said a suicide car bomber killed three policemen and seven civilians when he drove at their patrol in the central commercial district of Karrada around 7 a.m. A second, similar attack killed seven civilians, they said.

Two other cars exploded in the same area, several minutes apart, one near a Shiite mosque. Police and medical sources put the number of wounded at between 23 and 50.

Guerrillas have killed some 1,200 people, including around 120 US troops, since the Shiite-led government was formed two months ago. Minority Sunnis dominated Iraq under Saddam Hussein and are the majority in the rest of the Arab world.

Smoke and flames darkened the morning sky after the blasts. A bus lay charred outside Karrada’s post office, shop fronts and fruit stalls were devastated and trees were uprooted. In addition to the 18 dead, Wednesday night’s coordinated bomb attacks also wounded 48 in the Shiite Shula district of Baghdad, police said. The area’s main street was devastated.

The Al-Qaeda organization in Iraq, led by Jordanian Abu Musab Al-Zarqawi, claimed responsibility for a “Sunni reprisal raid”. Later, three further groups, notably Ansar Al-Sunna, laid claim collectively to the bombings.

US officials said the CIA believed guerrillas might be using Iraq to improve methods to pose a greater threat to the United States than those like Al Qaeda leader Osama Bin Laden who learned their trade fighting Soviet troops in Afghanistan.

In Brussels on Wednesday, foreign leaders endorsed Iraqi government commitments to draw Sunnis into the political process. Many from the minority community failed to vote in January elections.