At least 61 people have been killed by a bomb in Baghdad's predominantly Shia neighbourhood of Sadr City, an interior ministry official has said.
Police said 116 people were also wounded in the blast that took place at the popular market on Wednesday.
The explosion, caused by a motorcycle rickshaw loaded with explosives and covered with fruit and vegetables, happened in the north Baghdad district at around 7.30pm (1630GMT), according to one official.
Women and children were among the casualties and dozens of market kiosks were damaged, the official said.
The attacker got off the motorcycle rickshaw in the middle of Mraidi market and managed to escape before the bomb was set off, he said.
The attack comes a few days after US combat troops handed over the neighbourhood to Iraqi forces.
US troops plan to pull out of Iraqi cities, towns and villages by June 30.
Violence has dropped markedly in Iraq in recent months, with May seeing the lowest Iraqi death toll since the 2003 invasion.
But attacks remain common, particularly in Baghdad and the main northern city of Mosul.
Nuri al-Maliki, the prime minister, warned earlier this month that attacks were likely to increase in the coming weeks in a bid to undermine confidence in the Iraqi security forces.