Delhi Police have stepped up security around the CPI - M office here after the party received telephone calls threatening its general secretary Sitaram Yechury for supporting Jawaharlal Nehru University (JNU) students slapped with sedition charges.
A case has been registered on a complaint that three threatening calls were made at a landline number of the headquarters of Communist Party of India - Marxist here on Sunday night, Deputy Commissioner of Police Jatin Narwal told IANS.
"The caller allegedly used filthy language against Sitaram Yechury. "
Security has been beefed up outside the CPI - M office after the threatening calls, Narwal said.
He said the caller identified himself as an "Aam Aadmi Balveer Sena" member.
Meanwhile, students of the university have gone on strike, demanding release of JNU Students' Union president Kanhaiya Kumar, who is due to be presented before a city court on Monday.
Scores of JNU students formed a human chain and raised slogans on Sunday, demanding that sedition charges against Kanhaiya Kumar be dropped.
Kumar was arrested last week in a case of sedition and criminal conspiracy filed over holding an event marking the anniversary of Parliament attack convict Afzal Guru's execution, during which anti - India slogans were raised.