Anti-government demonstrators faced off against followers of influential cleric Moqtada Al Sadr across Iraq on Tuesday, a day after one demonstrator was killed in a clash between the two sides.
Mr Al Sadr, a militiaman-turned-politician, backed the anti-government rallies when they broke out in October but has split with demonstrators over the nomination of Mohammed Allawi as prime minister.
The cleric endorsed Mr Allawi while protesters rejected him, saying he was too close to the ruling elite they had been rallying against for four months.
In the southern city of Diwaniyah on Tuesday, the rift escalated into a fistfight between young anti-regime demonstrators and backers of Mr Al Sadr, recognisable by their blue caps.
Security troops were outside schools and government offices to try to ensure they reopened fully after sit-ins forced them to shut.
The Interior Ministry late on Monday said it had ordered reinforcements to schools, and a few students were trickling in the next morning.
But hundreds refused to go back to class, marching through the main anti-government protest camp with Iraqi flags and a banner that read, "Protest march for Diwaniyah high schools".
In Nasiriyah, all schools reopened after police were posted at them, Education Directorate spokesman Halim Al Hossayni said.
But students also took to the streets there, insisting on keeping up their protests.
"We're determined to pursue our peaceful movement in Habbubi Square because we want a homeland free of corruption and sectarian people," Hamad Ali said.
On Monday, a demonstrator was stabbed to death and three wounded after men in blue caps attacked an anti-regime rally, medics and security sources said.
Mr Allawi, 65, was nominated on February 1 after two months of political stalemate over who would replace former premier Adel Abdul Mahdi, who resigned in December.
