Police have intensified their efforts to arrest four persons who were recently identified as accused in the alleged murder of professor H S Sabharwal, official sources said on Sunday.

They are collecting details about the immovable poperties of the four persons so that they can be attached, in case they remain elusive, sources said.

It was learnt that the CID, which is probing the murder case and has not yet disclosed the identities of the accused officially, had asked the local police to arrest them as early as possible, sources said.

According to a senior officer, "Since their names figured in the CID records in the case, they are not being sighted in Ujjain and therefore, it is a routine procedure to start attaching their immovable properties to build pressure on them for arrest."

Though they are elusive, police have not yet declared that they were absconding officially, sources said.

CID Additional Director General of Police Vijay Raman is also camping in the city to increase the pressure to arrest the four persons, they said.

So far, police have arrested two ABVP leaders -- Shashiranjan Singh Akela and Vimal Tomar -- for their alleged involvement in the murder of Sabharwal, who died after he was allegedly assaulted during college union polls on August 26.

The duo are currently under judicial custody till September 29.

Meanwhile, a delegation of opposition MLAs will visit Madhav College where Sabharwal taught and meet his family members.