Bombings and shootings ripped across Iraq on Monday, killing at least 103 people in the deadliest day this year. The coordinated attacks in 13 cities sent a chilling warning that al-Qaeda is slowly resurging in the security vacuum created by a weak government in Baghdad and the departure of the U.S. military seven months ago.

Though there was no immediate claim of responsibility, the leader of al-Qaeda in Iraq declared on Sunday a new offensive aimed at sowing instability across the country.

Iraqi militants have kept up a steady drumbeat of deadly attacks since the U.S. pulled out in December, ending nearly a decade of war. They have sought to deepen the chaos created by the deepening sectarian political crisis that pits Sunni and Kurdish leaders against Shia political powers. The latest violence bore most of the hallmarks of al-Qaeda — the bombings and shootings all took place within a few hours of each other and struck mostly at security forces and government offices, favourite targets of the predominantly Sunni militants.

Nearly 200 people were wounded during the onslaught.

Sixteen people were killed in the single attack, and a police colonel died in a Sunni neighbourhood in Baghdad by a bomb hidden on his car.

“The worst attack was in the town of Taji, about 20 km north of the capital. Police said bombs planted around five houses in the Sunni town exploded an hour after dawn, followed by a suicide bomber who detonated his explosives belt in the crowd of police who rushed to help. In all, 41 people were killed, police said.

And in a brazen attack on Iraq’s military, three carloads of gunmen pulled up at an army base near the northeast town of town of Udaim and started firing at forces. Thirteen soldiers were killed, and the gunmen escaped before they could be caught, two senior police officials said.

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