Bhubaneswar, Jan 7 (IANS): An anonymous letter mentioning about a conspiracy to kill Odisha Chief Minister Naveen Patnaik was sent to his residence Naveen Niwas here, forcing the home department to take steps to tighten the security of the Chief Minister.

The letter said some contract killers armed with latest weapons like AK-47 and semi-automatic pistols are out to kill the Chief Minister. It said that these contract killers are professional criminals and they can kill the Chief Minister at any time.

"These criminals can attack you any time. I would like to tell you that you can be killed at any time. So please be aware that these contract killers are continuously following you. The mastermind lives in Nagpur," read the handwritten letter.

"The weapons which will be used to kill you have been brought to Odisha," it said.

The anonymous letter mentioned a list of 17 cars with registration numbers of Chhattisgarh, West Bengal, Punjab, Odisha, Delhi, Haryana, Sikkim and Maharashtra. The sender said the criminals are following Patnaik in the cars.

After receiving the letter, home department special secretary Santosh Bala directed the DGP, Intelligence Director and the Bhubaneswar-Cuttack Police Commissioner to probe the matter thoroughly and take appropriate action as deemed proper.

"The security of the Chief Minister may be assessed and tightened at his residence, secretariat as well as during journey to various places/functions if required," said Bala.