Iraqi authorities say a truck bomb in Baghdad has killed at least 78 people and wounded at least 218 others in the deadliest attack in the capital since April.
The explosion on Tuesday near a Shi'ite mosque in central Baghdad sent smoke billowing into the sky, and gunshots rang out across the city afterwards.
The attack came two days after authorities lifted a city-wide curfew put in place to stop sectarian attacks after last week's bombing of a revered Shi'ite shrine in Samarra.
Meanwhile, the U.S. military launched a major operation against al-Qaida in Iraq terrorists operating northeast of Baghdad. It says 10-thousand soldiers are taking part in the offensive in and around Baquba. Twenty-two militants were killed in the early hours of the operation.
Iraqi officials say at least 30 people were killed before clashes died down in Nasiriyah between Iraqi police and Mahdi Army Shi'ite militiamen.
In other news, Iraq's National Security Advisor Mouaffac al-Rubaie has vowed that in coming weeks, Iraqis would see many big operations to destroy al-Qaida and its supporters.
In Baghdad, a U.S. soldier was killed when gunmen attacked his patrol Monday.
On Monday, President Bush held a video conference with Iraqi leaders on political, economic and security reforms in Iraq. White House spokesman Tony Snow says Washington believes Iraqi leaders are now "very serious" about moving forward on key issues.