The Chhatra League is the student affiliate of the ruling Awami League.
The university authorities have identified 21 BCL activists involved with the assault and handed over six of them to the police.
Students of the Jagannath and SM Hall of the Dhaka University said up to 12 activists of the ruling party had been extorting money from vehicles on the Fuller Road from Saturday midnight to celebrate Pahela Boishakh.
Several journalists went to the spot at around 4am to check this out and found Chhatra League activists trying to stop a motorcycle.
As the journalists inquired about their identity, the extortionists said they were from the Chhatra League's SM Hall unit of Dhaka University.
One of them, identified as ‘Asif’, is a second year student of the university’s Mass Communication and Journalism department.
Prothom Alo’s university’s correspondent Ahmed Zaif talked Asif out of the pack, but other activists tried to take him away.
Several Chhatra League activists indiscriminately beat up Zaif, Bangladesh Sangbad Sangstha’s university correspondent Moloy Kumar Dutta, journalism department's Dulal Samaddar, bdnews24.com’s Sujon Mondol and Daily Star’s Protik Chakrabarty.
They also attacked Prothom Alo’s senior correspondent Shariful Hasan as he tried to mediate.
The activists brought out sticks from the nearby SM Hall and beat up the journalists a second time.