Police have identified four persons who were believed to be involved in the kidnapping, Western Range Inspector General of Police A M Prasad said.
The daughter of the Communist Party of India-Marxist MLA from Manjeshwar in Kerala, C K Kunhambu, was returning to Mangalore with a friend when they were forcibly asked by some persons to alight from the bus and get into an auto-rickshaw.
They were subsequently released. Preliminary information available with the police said the girl was believed to be travelling with a boy belonging to a minority community.