Students of different schools, colleges and universities gave the government a 48-hour ultimatum during their demonstrations in the capital on Tuesday to realise their demand for half-fares of buses.
The ultimatum came from a demonstration programme at Bakshibazar in the capital in the morning.
Addressing the programme, they also raised a demand for ensuring a safe journey for woman and female students.
The protesters threatened if their demands are not met, they will start a fresh protest programme at Nilkhet in the capital on Thursday.
Introducing him as a chief coordinator of the seven-college movement, Ismail Samrat said all public transport should take half fares from students and the authorities concerned should issue a gazette notification immediately to this effect.
He urged the government to satisfy the demands, otherwise the protesters will not leave the road.
Meanwhile, a group of students from Dhaka College attacked the protesting students in the afternoon. The incident took place near Science Laboratory intersection around 1:30pm.
According to police, students from Ideal College, City College and Dhaka College blocked the Science Laboratory intersection around 12:30pm and began to chant slogans, demanding that buses accept the student discount.
Police are still working to control the students on the scene, said Inspector Saiful Islam of Dhanmondi Police Station.
Student protesters wrote slogans on the buses, using spray and markers, said Mahmud Zaman Ovi, a photojournalist of bdnews24.com.
They brought out a procession and moved around the nearby roads, he said. Some university students joined them.
At one point, a group of 50 to 60 students from Dhaka College swooped on the student protesters with batons, alleging that a Dhaka College student had been physically assaulted by the protesters.
The violence brought traffic to a halt in the area around 2.15pm.
As part of their ongoing protests, students of different educational institutions in the capital blocked the road at Mohammadpur bus stand in the capital on Monday morning, demanding half fares of buses.
Students chanted slogans in front of Allah Karim Jame Mosque at Mohammadpur bus stand demanding half fare or half pass.
On Sunday, students of Badrunnessa Government Girls College also blocked Bakshibazar intersection in the capital, protesting against the harassment of a student by a bus worker over a half-fare issue.
On Saturday, the helper of a bus driver of 'Thikana Paribahan' harassed a college student when she gave him half-fare.
Protesting against the incident, students of the college brought out processions from their campus in the morning, demanding punishment for the transport worker.
As the protesters staged a sit-in on the road, the vehicular movement came to a grinding halt.
The students of Dhaka College, Shaikh Burhanuddin Post Graduate College, Government Titumir College, Tejgaon College also joined the protest programme.
Earlier on Saturday, 10 buses were vandalised by the students of Dhaka College and City College, demanding that the government fix half-fares of buses.