Iraq declared a curfew in Baghdad on Monday from midnight (2100 GMT) until 6 a.m. (0300 GMT) as renewed anti-government protests in which over 200 people have been killed entered a fourth day with students joining in.
State TV cited the Baghdad Operations Commander as giving the order, which it said was effective "until further notice".
Security forces on Monday fired tear gas at school and university students who defied a warning from Prime Minister Adel Abdul Mahdi and joined the protests.
A spokesman for Abdul Mahdi, whose position is increasingly precarious as he faces the largest challenge since he came to power a year ago, said on Sunday that anyone disrupting work or school days would be punished.
Mass street protests in Baghdad and other cities in the southern Shi'te heartland against economic hardship began at the start of the month and resumed on Friday after a pause of about two weeks.
Thousands of Iraqi protesters gathered in Baghdad's central Tahrir Square on Sunday, defying a bloody crackdown that had killed scores over the previous two days, and an overnight raid by security forces seeking to disperse them.