New Delhi: Scores of JNU students laid siege to the university's administrative block on Thursday to protest the registrar's decision to put off an academic council meeting where students and teachers wanted to oppose the introduction of attendance.

Around 10pm, 40 teachers led by Sanskrit professor Hari Ram Mishra were prevented from entering the building to "rescue" the two rectors in the block.

Around 11pm, guards escorted rectors Chintamani Mahapatra and Rana Pratap Singh out through the group of sloganeering students, after almost 10 hours of confinement. They left in an ambulance.

Protests against attendance started after it was imposed last month - for first time in JNU's 49-year history - after an academic council resolution that students and teachers claim was passed without discussion.

Most students have been refusing to sign attendance sheets after the move was rejected by general body meetings at several academic centres and the JNU Teachers' Association has been supporting the protest led by the JNU Students' Union - which breached a Delhi High Court ban on protests within 100 metres of the administrative block.

Around 11.30am on Thursday, JNUSU representatives led by its president Geeta Kumari went inside the building asking to meet the VC, but were refused. Around 1.25pm, as rectors Chintamani Mahapatra and Rana Pratap Singh tried to leave the building for lunch, they were stopped by students.

"We asked them to tell the VC that he has to meet us and cannot continue to unilaterally run JNU without talking to students. During his monthly interaction, he does not meet the office-bearers (of JNUSU) together and communicates only with threats of expulsion from classes and hostels," Geeta said

The registrar sent a notice through guards to the four main JNUSU leaders, including Geeta, around 2pm saying a discussion would only be held after the students disperse.

The JNUSU sent in two more letters at 2.30pm and 3.30pm, addressed to the VC - assuming he was in the building. At 4pm, Mahapatra walked out through an entrance to the security room, which students realised only after he had walked about 100 metres.

Several students ran after him and surrounded him, raising slogans such as " bahut hua samman tumhari aisi taisi (Enough respect, to hell with you) from the film Mukkabaaz and he was escorted back by JNUSU leaders.

Soon after, a police sub inspector - visiting the building for CCTV footage for a theft case - was heckled by students and he left.

Around 6pm, chief proctor Kaushal Kumar was gheraoed as he tried to leave from a back gate. Kumar remained seated in a parking lot outside - surrounded by students asking him to call the VC - for an hour before students let him go.

"I knew they wouldn't hit me," he told reporters later. "And I kept my cool even though they called me names. Even they know that the public will never accept this demand against attendance."

Even as the gherao went on, teachers took classes and conducted tests in several open spaces on the 1,000-acre campus.

French professor Ajith Kanna, who came to the administrative block, told this paper: "Most students have a positive attitude and most teachers are supporting the cause of the students. Attendance is anti-intellectual, and unintelligent ways of dealing with students are unacceptable.... Students drop courses where the professor is not good and choose courses that are well-taught. Adults can choose for themselves."

VC M. Jagadesh Kumar, who faced a gherao in 2016 after a student went missing after alleged assault by the Akhil Bharatiya Vidyarthi Parishad, put out several tweets condemning the "unrest."

A statement from the registrar, quoting the Delhi High Court order that asks the administration to call the police if protests take place in the restricted area, said: "I sincerely appeal to the students who have confined the rectors for so many hours to allow them to go home."

Chief proctor Kaushal Kumar and public relations officer Poonam Kudaisya said they were unaware where the VC was. Rector Mahapatra told this reporter that his health was not good, but did not reveal the whereabouts of the VC - who did not received calls or reply to messages from this paper.

A JNUSU statement said: "The registrar is lying on the face and is trying to divert the issue of compulsory attendance and their incompetence. Students have been peacefully waiting to meet JNU VC and raise questions about compulsory attendance.... The VC's way of running a university through social media and waving circulars, trampling upon all attempts at reasoned dialogue and spreading lies is extremely shameful. We demand the VC to meet the students and not resort to slander and lies."