A suicide bomber detonated an explosives-packed car near a funeral procession in southeastern Baghdad on Friday, killing at least 28 people in the latest brazen attack since the U.S. troop withdrawal, officials said.

Police officials said the blast occurred at 11 a.m. in the predominantly Shiite neighborhood of Zafaraniyah, where mourners had gathered for the funeral of a person killed the day before. They said 61 people were wounded in the attack.

Hospital officials confirmed the death toll. All officials spoke on condition of anonymity because they weren’t authorized to release the information.

Salam Hussein, a 42-year-old grocery store owner in Zafaraniyah said he was watching the funeral procession, which was guarded by several police cars, when the blast blew out his store windows and injured one of his workers.

“It was a huge explosion,” Mr. Hussein said. As he took his worker to the hospital, Mr. Hussein said he saw cars engulfed in flames, “human flesh scattered around and several mutilated bodies in a pool of blood” around where the attacker’s car had exploded.

Across Iraq, at least 200 people have been killed in a wave of attacks by suspected insurgents since the beginning of the year, raising concerns that the surge in violence and an escalating political crisis might deteriorate into a civil war, just weeks after the U.S. military withdrawal.

Most of the dead have been Shiite pilgrims and members of the Iraqi security forces.

There was no immediate claim of responsibility for Friday’s attack.

Since the U.S. completed its pullout last month, militant groups—mainly al Qaeda in Iraq—have stepped up attacks targeting the country’s majority Shiites to undermine confidence in the Shiite-led government and its efforts to protect people without American backup.

On Thursday, 17 people died in bombings around the country, including seven people in attacks on Baghdad’s s two predominantly Sunni districts, suggesting that Shiite militants could be retaliating amid fears of a reignited sectarian conflict in the war-ravaged country.