In a statement issued by Dahiya, he also alleged that when he reached the spot to help students enter the examination hall, the student groups attacked him.
Exams for undergraduate and postgraduate courses are currently underway in Delhi University.
"A handful of students were preventing the entire faculty from appearing, also claiming falsely that the examination would happen later," Dahiya said.
"The students called me for help and when I went there, I was attacked," he added.
DUSU, along with the ABVP, had issued a statement earlier supporting the Citizenship Amendment Act (CAA).
Both organisations had also skipped the Sunday night protest at Police Headquarters at ITO that was called in solidarity with the Jamia Millia Islamia University students and also against the CAA.
"We reject any lockdown call for DU. We condemn the act of such violent perpetrators and such environment building cannot be tolerated," DUSU said in a statement on Monday.
On Sunday, residents and commuters in the heart of the national capital were seen running in panic as a raging mob of almost 1,000 people protested against the CAA.
At least five buses were set ablaze by the mob. Besides, various cars and motorcycles were also targeted.
Two fire brigade officials were injured in stone pelting as protests against the newly enacted Citizenship (Amendment) Act 2019 took place in parts of south Delhi for almost an hour with the mob indulging in arson and vandalism and threatening residents.
( With inputs from IANS )