BAGHDAD — Back-to-back bomb blasts ripped through one of the holiest cities in Shiite Islam Sunday, killing at least 10 people and injuring dozens in a community still reeling from a deadly bus hijacking earlier this month that left Iraq's Shiites again feeling hunted.
Four explosions struck the city of Karbala over a five-minute period, government officials said, sending thick black smoke over the city. Two of the bombs targeted an Interior Ministry office that issues ID cards. Another struck near a house, shredding its walls and ceiling. And one of the explosions went off half a mile from an important gold-domed shrine.
"Once again, the terrorist enemies of both Iraq and humanity have committed a new crime against the innocent people of Karbala," said Prime Minister Nouri al-Maliki, a Shiite.
He called the bombings a "heinous crime," and promised those behind them and the earlier attack on the bus would be punished. He also warned people not to be drawn back into sectarian revenge killings.
Ferocious bombing attacks by Sunni insurgent groups such as al-Qaida in Iraq targeted the Shiite community whose leaders came to power after the fall of Saddam Hussein. The bloodshed pushed the nation to the edge of civil war.
Violence in Iraq has fallen dramatically since the bloodletting of 2006 and 2007, but militant attacks still appear aimed at re-igniting the nation's volatile ethnic and religious divide.
The Sept. 12 bus attack targeted Shiite pilgrims from Karbala who were headed to a shrine in neighboring Syria.
The gunmen stopped the bus at a fake checkpoint in the western desert of Anbar province, heavily populated by Sunnis and once one of the heartlands of the insurgency.
The assailants pulled 22 men from the bus and shot them execution-style, leaving the women and children weeping beside a remote highway.
Al-Maliki has been trying to tamp down tensions between officials in Karbala and Anbar since the highjacking. Four suspects are being held in the case, and al-Maliki's military advisers say at least some foreigners were among the plotters.
Sunday's bombings in Karbala were meant to raise tensions further, officials said.