About 25 students have been injured in clashes in Bangladesh on the seventh day of an unprecedented youth protest about road safety, reports say.
Thousands of pupils, many in school uniform, have been out on the roads of the capital, Dhaka, stopping traffic and checking vehicles and drivers.
The authorities say unidentified groups of youths attacked them on Saturday.
The protesters want improved road safety after a boy and girl were killed by a speeding bus last Sunday.
Transport workers have in recent days staged their own strike, while the government has urged students to return to their classrooms.
A government minister previously accused the students of hypocrisy, sparking further uproar. He later apologised.
Police used tear gas as they tried to control the crowds on Saturday.
Local journalists told the BBC they were among those beaten up by pro-government students, and they reported having their camera equipment destroyed.
Amid reports of sexual assaults in the streets, a female reporter alleged on social media that she had been "molested" while trying to film the clashes.
"We won't leave the roads until our demands are met. We want safe roads and safe drivers," said protester Al Miran to AFP news agency.
Chanting "We want justice", students have been calling for stricter enforcement of traffic laws, and have blocked major intersections in the capital for seven consecutive days.
Teens as young as 13 have been seen on Dhaka's notoriously clogged streets, checking drivers have valid licences and that cars and buses are in roadworthy conditions before letting them drive on.