Twenty-two people were killed and 55 wounded in clashes in Baghdad, police said on Sunday, the worst eruption of violence in the capital since Shi'ite cleric Moqtada al-Sadr called his fighters off the streets a week ago.
The violence in Sadr's Baghdad stronghold, the Shi'ite slum of Sadr City, follows a week of relative calm after a crackdown by Prime Minister Nuri al-Maliki on Sadr's followers led to battles across the south and Baghdad late last month.
In a reminder of instability further north, a group of roughly 40 students were kidnapped by gunmen for several hours near the city of Mosul before Iraqi security forces freed them.
The unrest comes only days before U.S. ambassador Ryan Crocker and U.S. commander General David Petraeus are due to deliver key testimony to the U.S. Congress on progress in Iraq.
Gunfire could be heard throughout the day in Sadr City, the stronghold of Sadr's Mehdi Army and home to 2 million people in eastern Baghdad.
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