BAGHDAD — Three car bombs tore through Baghdad and the former insurgent stronghold of Fallujah on Sunday, killing at least 36 people and breaking what had been a period of relative calm since the end of the Muslim holy month of Ramadan.
The violence was the worst to strike Iraq since the number of American troops in the country dropped below 50,000 and the US declared a formal end to combat operations. It also underlines the challenges Iraqi security forces face trying to stabilize Baghdad as the US trims its military presence and Iraq's police and military assume responsibility for security.
The deadliest attack Sunday took place in north Baghdad's Kazimiyah neighborhood when a car bomb detonated near a branch office of the National Security Ministry in Adan square, killing at least 21 people and wounding more than 70, police and hospital officials said.
"It was a big explosion and dust and smoke filled my house," said Abu Shahad, who lives about 200 yards (meters) from the blast site. "I went out and saw a big black cloud hanging over the area where the bomb exploded, and I rushed there because I have relatives living there."