Former Congress legislator Asif Mohammed, Jamia Millia Islamia student Chandan Kumar, who is also a member of the Left-backed All India Students’ Union (AISA), and local politician Ashu Khan on Friday joined the probe in connection with cases of violence and vandalism during protests against the Citizenship (Amendmet) Act or CAA in Delhi’s Jamia Nagar and New Friends Colony last month.

The three reached the office of Delhi Police’s crime branch in Chanakyapuri after the Special Investigation Team (SIT) probing the cases served them notices on Thursday, asking them to join the investigation and record their statement, deputy commissioner of police (crime) Rajesh Deo, who is heading the SIT, confirmed.

The three were named in the FIR registered at the Jamia Nagar police station regarding the violent protest, said the police.

The SIT has also detained one more suspect, identified as Furkan, and is questioning him in connection with the violence in New Friends Colony (NFC) on December 15. At least five buses were torched and more than 100 public and private vehicles damaged when the anti-CAA protests turned violent. Hundreds of people, including Jamia students, took part in the protest.

More than 30 people, including Jamia students and police personnel, were injured as the protesters pelted stones, glass bottles and tube lights on security personnel, who in turn fired tear gas shells and resorted to lathicharge.

Furkan is being questioned over his role in the violence. The police want to confront him with evidence and video clippings in which he is allegedly seen participating in the violent protest and damaging public and private vehicles, said an SIT official.

“We have detained Furkan and interrogating him. A decision on his arrest is yet to be taken. Asif Mohammed, Ashu Khan and Chandan Kumar are also being questioned in the cases,” said DCP Deo.

According to the SIT official, Furkan was picked up from Jamia Nagar area by the police on Thursday morning. As he was taken to the police station, many people led by a local politician assembled there and protested against his detention. They demanded the release of Furkan, said a police officer, who did not want to be named.

The protesters left when they were informed that Furkan was already handed over to the SIT, which has been probing all the 10 cases registered at eight different police stations across South, Northeast, Central and Shahdara districts following the violence and vandalims during anti-CAA protests, the officer added.

A total of 99 people have already been arrested in connection with the 10 cases. Many of them have been granted bail.