The Kerala police received an anonymous telephone call threatening to kill Kerala Chief Minister V S Achuthanandan in 24 hours, a top police official said.

Achuthanandan will be done away within 24 hours, an anonymous caller informed a constable on duty at 0410 hours on Monday over phone, Police Commissioner Balramkumar Upadhaya said.

Upadhaya said the call had been traced to West Asia and further investigation was on.

However, he said the exact location from where the call originated was yet to be ascertained.

Stating that the motive behind the call could be to create panic, Upadhaya said police headquarters at Thiruvananthapuram had been alerted for necessary action.

Upadhaya said he had information that similar anonymous calls had been received at the police commissioner's office in the state capital.

Meanwhile, security has been tightened in and around the chief minister's office at Thiruvananthapuram following the threat, sources said.

However, there was no change in the itinerary of Achuthanandan, they added.