20 people have been killed and 60 wounded after a car bomb exploded in the Karrada district of central Baghdad.
At least one building and several cars were ablaze after the blast in the predominantly Shia area.
Short bursts of gunfire could be heard soon after the explosion.
Karrada, normally one of Baghdad's most stable areas, was hit by three separate blasts on Monday which killed 13 people.
Earlier, a parked car bomb killed seven people and wounded 45 near a popular kebab restaurant and shops in the city of Kirkuk, 250km north of Baghdad.
The US military began a security crackdown in Baghdad five months ago in an attempt to stem bombings, many of them blamed on Sunni Islamist al Qaeda, and sectarian killings between majority Shia and minority Sunni Arabs.
US and Iraqi forces later launched another big operation in mid-June in areas around Baghdad after the crackdown in the capital forced al-Qaeda fighters and insurgents out of the capital into surrounding provinces.
