BAGHDAD — A truck bomb tore through an outdoor vegetable market in northeastern Iraq, the deadliest of a series of attacks Thursday that killed at least 48 people, officials said.

The explosion in the town of Sadiyah, some 140 kilometers (90 miles) northeast of Baghdad, is the latest in a wave of attacks that has swept across Iraq since April, pushing violence to levels unseen since the country teetered on the brink of civil war in 2006 and 2007.

Two police officers said witnesses told them that a man parked the truck containing the bomb in the market and asked workers to unload the vegetables before leaving the vehicle. The officers said 31 people were killed and at least 45 people were also wounded in the attack.

Two medical officials confirmed the casualty figures.

Meanwhile Thursday, a suicide bomber set off his explosives-laden belt at an army checkpoint in the town of Taji north of Baghdad, killing six soldiers and wounding 12, a police officer and a medical official said.

In Baghdad's northern Kasra neighborhood, a bomb attached to an army officer's car killed his son and wounded five civilian pedestrians, a police officer and a medical official said. The officer was not in the car at the time of the explosion, authorities said.

A car bomb explosion followed by other two bombs in a commercial area of Baghdad's western Amiriyah neighborhood killed eight civilians and wounded 15, a police officer and a medical official said.

And in Baghdad's southeastern Bayaa neighborhood, gunmen attacked a supermarket, killing the two brothers who own it, a police officer and a medical official said. Two shoppers were wounded, they said.

All officials spoke on condition of anonymity as they were not authorized to release information to journalists.

The attacks came a day after a series of coordinated explosions hit mainly Shiite commercial areas in Baghdad and outside the capital, killing at least 35 people and wounding 120.

Last Thursday, a suicide bomber struck a group of Shiites gathered in Sadiyah to commemorate the 7th century death of a revered Shiite shrine. That attack killed at least 32 people and wounded 75.

There was no immediate claim of responsibility for the attacks, but suicide attacks and large-scale bombings — especially against security forces or crowded markets in Shiite areas — are a favorite tactic of al-Qaida's local branch and Sunni insurgents. The Sunni extremists launch such attacks as they view Shiites as heretics.

Violence in Iraq in the past eight months has killed more than 5,500, according to the United Nations. Thursday's explosion brings the death toll across the country this month to 292, according to an Associated Press count.