After bombings, Iraq authorities detain 10 security officials

In an almost unprecedented public admission that Iraqi security forces who took over sole responsibility for Baghdad in July have not been up to the job, Iraqi officials are investigating 11 security commanders for negligence.

On Wednesday, trucks loaded with huge plastic containers of explosives managed to approach two government ministries on major roads despite a ban, resulting in the capital's deadliest bombings in 18 months.

"We are investigating them because the violations happened in areas under their control," says Baghdad security spokesman Brig. Gen. Mohammad al-Askari, adding that he believes Iraq can still maintain security in the capital. He says they are not contemplating asking for help from American forces, who pulled out of the city on June 30 in line with the US-Iraqi security agreement.

The bombings outside the foreign and finance ministries killed more than 100 Iraqis and wounded more than 500 in the most devastating attack in the capital since February 2008. Less than two months after US combat forces withdrew from Baghdad, the attacks have also weakened many Iraqis' belief that the improved security of the past year would last.

Prime Minister Nouri al-Malaki and senior officials met late into the night after the attacks to reassess security measures. The government had pledged to remove concrete blast walls from the city's main roads and reopen streets closed to traffic by mid-September, but now residents expect them to stay.

Less than 48 hours before the expected start of Islam's holy fasting month of Ramadan, security forces blanketed the city, imposing tighter security around government buildings and increasing searches at checkpoints. Many of the victims of the bombing were buried Thursday. At other ministries and some businesses, Iraqis fearing more attacks stayed away from work.

Truck bombs made from fertilizer

Askari, the military spokesman, earlier told Al Arabiya television that seized documents showed that an alliance of Sunni insurgents and Saddam Hussein loyalists planned the attacks after June 30 in an attempt to force the Iraqi government to call US forces back in. He said that was aimed at allowing the insurgent groups to resume attacks on American soldiers and showing that Iraq was not committed to a US withdrawal.

In what appeared to be the first details of the coordinated bombings, Askari said that the truck bombs had been assembled in an industrial area of Baghdad and consisted of common sodium nitrate and chemical fertilizer as well as mortars and rockets that exploded when the suicide bomber detonated the vehicles.

The explosive agents were packed into large fiberglass containers of the kind sold in many streets in Baghdad. The hand-held detectors used at checkpoints to identify explosive agents apparently are ineffective against fiberglass.

Trucks are not allowed on major roads in the city during daylight. Askari said traffic police had tried to stop the truck bomb on the road to the foreign ministry. He said policemen on motorcycles pursued it and alerted the ministry but the suicide bomber managed to reach the building and detonate the truck. The traffic police who had been pursuing the suicide bomber are presumed to have died in the explosion.

•Awadh al-Taee contributed to this report.