Residents inspect the remains of a vehicle used in a bomb attack in the district of Abu Dsheer in southern Baghdad. The car bomb explosion near a market killed at least four people and wounded two dozen others. (STRINGER/IRAQ/REUTERS)

At least 35 people were killed and more than 80 wounded across Iraq on Thursday, most of them in a suicide attack on a police compound, as a wave of bombings and assassinations continued to unsettle the country.

Shortly after sunrise, a suicide bomber rammed a small Hyundai bus packed with an estimated 300 pounds of explosives just inside a protective blast wall around a police station in the Shiite city of Hilla, about 60 miles south of the Iraqi capital, police said.

The explosion killed 29 people and wounded 73 — almost all Iraqi police officers — in the deadliest attack in the country since late March.

Iraqi police Capt. Fadhel Chenchun said the blast appeared orchestrated to take advantage of a shift change, when more officers than usual were in the station and commotion at a checkpoint leading to a secure parking area may have helped the bomber penetrate the area.

Most of the officers killed were in the middle of a morning calisthenics and sports routine, Chenchun said.

It was the second major bombing in Iraq since President Obama announced the death of al-Qaeda leader Osama bin Laden. On Tuesday night, at least 16 people were killed and 35 others were wounded when a suicide attacker detonated a car bomb outside a cafe in Baghdad that was crowded with Iraqis watching a soccer match.

Chenchun, without citing specific evidence, said he saw a connection between the attacks and the covert U.S. operation in Pakistan. “I accuse al-Qaeda of being behind these events as a retaliation for the killing of Osama bin Laden,” he said.

Local Shiite politicians echoed that sentiment and also blamed al-Qaeda, which has conducted attacks in the city before. There were no immediate assertions of responsibility for the attack.

The bombing came amid a wider uptick in violence in Iraq over the past two weeks and a rash of assassinations of government workers and security leaders that has left nearly 70 dead since early April.

Also Thursday, in one of at least four separate incidents in northern Iraq, a bomb targeting Kurdish security officials killed two and wounded seven near Kirkuk. And in Baghdad, gunmen using silenced weapons assassinated an Iraqi army brigadier general.

Special correspondent Asaad Majeed contributed to this report.