More than 100 Iraqis have been killed and 150 injured acrossthe country on a day when the new USambassador to Iraqwas sworn in.

At least 122 people died and scores were injured when fivesuicide bombers attacked popular Shia markets in Khalis and the Shaab districtin Baghdad onThursday.

Thursday's toll pushed to more than 300 the number of Iraqiskilled in the most violent 48 hours in months.

The bombers struck during the busiest time of the day. TheKhalis market was especially crowded as government flour rations had reportedlyjust arrived for the first time in six months.

Bloody backdrop

At least 43 people were killed and 86 wounded by the threesuicide vehicle bombs there, including an explosives-packed ambulance, policesaid.

In the north Baghdad bombings, two suicide attackers wearingexplosives vests blew themselves up the Shalal market in the predominantly ShiaShaab neighbourhood.

At least 79 people were killed and 81 wounded as theyjammed the market to buy provisions on the eve of the Muslim day of rest andprayer.

The bombings formed a bloody backdrop to theswearing-in of Ryan Crocker as the new USambassador to Iraq at the US embassy inBaghad's Green Zone.

Crocker pledged to stand by Nuri al-Maliki, Iraq's prime minister, and said that Iraq'sparliament must push ahead with reconciliation efforts.

"This government, under the leadership of primeminister Maliki, must continue to take the necessary steps to unify thiscountry, and to deliver tangible improvements to the lives of all Iraqis,"he said.

Crocker replaces Zalmay Khalilzad, who left the country thisweek.

In the Khalis attack, the first two cars exploded in quick successionat about 6pm on Thursday near a busy market in the centre of the town.

Corpse trap

They were followed by a third car bomb 45 minutes later thatwas detonated about 500 metres away, police said.

Earlier, five people were killed and nearly 20 otherswounded when a car bomb exploded in the town of Mahmudiya, 30km south of Baghdad,police said.

In the Iraqi capital, two policemen died and six werewounded when a car loaded with explosives and with a corpseinside blew up when they came to retrieve the body, a security official said.

Another two policemen were killed and two more wounded whenarmed men opened fire on a police convoy as it passed through adistrict in northern Baghdadnear the Sunni al-Nida mosque, an official said.

Three more Iraqis were killed and another 20 wounded in aroadside bomb explosion in Baghdad'ssouthwestern Baya district.

Sectarian tension

In Tal Afar, Durad Kashmula, the governor of Nineveh province,acknowledged a setback to the authorities' attempt to dealwith the recent surge in sectarian violence.

Hours after lorry bombs killed 85 people in aShia area of the town on Tuesday, up to 70 Sunni men were shot dead.

Tal Afar, situated close to the Syrian border, washeld up only a year ago by George Bush, the USpresident, as an example of progress towards peace.

On Thursday, Kashmula said at a news conference in Mosul:"Yes, there are policemen who are involved.

"They have been arrestedbut released afterwards due to demonstrations and to deter strife," hesaid, referring to the previous day's protests in Tal Afar.

Kashmula said they would be brought to justice in duecourse.

Brigadier Najim al-Jubouri, the mayor of Tal Afar, saidthat 18 people had been detained over the shootings.

It was not clear how many remained in custody on Thursday.

Salih Qadu, head doctor of Tal Afar hospital, said thebodies of 60 men shot in the aftermath had been brought to the hospital.

A senior Iraqi army officer put the toll from the attacks at70.