The Kozhikode police on Monday received an anonymous threat call which said that an attempt would be made on the life of Kerala Chief Minister VS Achuthanandan within 24 hours.
The security of the chief minister, who is in the state capital, was immediately stepped up after the police top brass was alerted.
The call in Malayalam, which came from Saudi Arabia, was received by a police constable in the City Commissioner's office in Kozhikode, police said.
However, there was no change in the scheduled programmes of the chief minister for the day, CMO sources said.
Efforts were on to trace the source of the call by tracking down the number displayed on the caller ID of the phone on which the call was received with Saudi Arabia's ISD code.