BAGHDAD, Iraq — A car bomb and a suicide attacker killed at least 11 people across Baghdad today as militants show increasing defiance to a major security operation in the capital.

More than 100 people have been killed in the Baghdad area since Sunday in a direct challenge to efforts by U.S. and Iraqi forces to restore some authority on the streets and give the embattled government some breathing room.

The attacks came during the busy morning rush for goods and fuel. A car rigged with explosives tore through a line of cars at a gas station in the Sadiyah district in southwestern Baghdad. Police said at least six people were killed and 14 injured in the neighborhood, which is mixed between the majority Shiites and Sunnis whose militant factions are blamed for many of the recent bombings and attacks.

Later, a suicide attacker drove a bomb-laden car into a vegetable market near a Shiite enclave in southern Baghdad. At least five people were killed and seven injured, police said. The same market in the mostly Sunni Dora district was targeted last month by three car bombs that killed 10 people.

Outside Baghdad, nearly 150 people were hospitalized complaining of breathing problems, vomiting and other ailments after a truck carrying a chlorine-based substance was hit by a roadside bomb north of Baghdad, said Brig. Gen. Qassim Moussawi, a military spokesman.

Two people died in the blast and the others were treated after being exposed to fumes and debris near Taji, about 12 miles northwest of Baghdad, Moussawi said. All those treated were in stable condition.

On Monday, insurgents staged a bold daylight assault against a U.S. combat post north of Baghdad, killing two soldiers and injuring 17. The U.S. military called it a "coordinated attack" — which began with a suicide car bombing and then gunfire on soldiers pinned down in a former Iraqi police station, where fuel storage tanks were set ablaze by the blast.

Mohammed al-Askari, spokesman for Iraq's Defense Ministry, blamed the attack on a cell of al-Qaida in Iraq, which has claimed responsibility for many high-profile strikes. "It's their work," he said.

Altogether, nine U.S. service members have been reported killed since the beginning of the weekend, six of them on Monday.

In Baghdad, Prime Minister Nouri al-Makiki moved quickly to try to defuse a potentially explosive scandal after a Sunni woman claimed she was raped by three officers of the Shiite-dominated police.

But the government's response — siding with the officers and trying to discredit the allegations — threatened to bring even more backlash.