As many as 22 people, mostly Congress workers, were arrested in Ujjain on Wednesday in connection with blackening the face of a professor, while more than 12 students owing allegiance to Akhil Bharatiya Vidyarthi Parishad were named as accused in the murder of Professor Harcharan Singh Sabharwal at the Madhav College in Ujjain on Saturday.

Ujjain Municipal Corporation chairperson Azad Yadav, City Youth Congress President Ravi Bhadoria, former corporator Yogesh Sharma and student leader Arun Sharma were among 22 people arrested for blackening the face of Prof M L Nath and ''violence'' during Ujjain bandh on Monday, police spokesman Rajesh Mishra said. Police had earlier claimed that the bandh was peaceful.

Five ABVP workers were arrested on Wednesday in connection with Prof Nath case and they were released on bail.

Police sources said nobody had been arrested so far for murdering Prof Sabharwal as students attacked him for postponing students union elections on Saturday.

Teachers of government and non-government colleges here handed over to the police a list of about 12 students naming them as accused in the murder of Prof Sabharwal. State ABVP president Shashi Ranjan Singh Akela, its Organising Secretary Vimal Tomar, besides five arrested ABVP workers were among those listed. Most of them had gone underground.

The teachers took out a silent rally and handed over the list to Divisional Commissioner and Range Inspector General on Wednesday.

IG M P Dwivedi, heading the Criminal Investigation Department team, started the probe after offering prayers at the Mahakal temple in Ujjain on Tuesday night.