A car bomb and several mortars today ripped through a central Baghdad district which had been relatively stable, killing at least 31 people and wounding 153 others, police sources said.
The car bomb, in the shopping district of Karrada, heavily damaged a building, raising fears the death toll could rise, said Ministry of Interior sources. The mortars landed nearby.
The explosion occurred about 200 yards from the house of Vice President Adil Abdul-Mahdi, a Shiite and a senior figure in the Supreme Council of the Islamic Revolution in Iraq, the country's biggest Shia party.
Although there have been bombings in Karrada before, the mostly Shia area has been one of the few relatively stable districts of the capital.
US and Iraqi forces have been focusing their efforts on stabilising Baghdad, racked by daily attacks from car bombs, suicide bombers and kidnappers.
Prime Minister Nuri al-Maliki told the US Congress that Iraq would "be the grave of terrorism and terrorists".
But the violence has been unrelenting and Thursday's blasts left a familiar scene of chaos in the Iraqi capital.
Inside a tailor shop destroyed by the bomb, people tried to pull a young man from beneath a collapsed ceiling. A boy of about 10 with a bloodied head lay on the floor a few feet away.
"My sister is there. My sister is there," one woman said to a man holding her hand. "She is probably alright," he said.
The US military may boost its force in Iraq by delaying the scheduled departure of some troops involved in routine rotations, officials said in Washington.