An anonymous letter that threatened to assassinate the chief ministers of Andhra Pradesh and Telangana, and also carry out suicide attacks on various establishments in the two states, has created a storm.

The handwritten letter in Telugu, claims that it would 'target' the chief ministers and blow up the AP Assembly, Vizag Airport, ISRO and DRDO buildings. 

According to a report in PTI, the letter originated from the Nirmal town of Adilabad district in Telangana, and was sent via post to the Visakhapatnam Airport Director.

The report adds that in view of the threat letter, security in and around the airport and other vital installations has been beefed up and additional forces have been deployed.

Visakhapatnam Police Commissioner Amit Garg also confirmed that the threat letter was received a few days ago.

However, an investigation into the incident, has led the police to believe that this letter could be a prank by miscreants.

According to a Times of India report, the letter was signed by B Narayan Singh, an electricity department lineman of Nirmal, and Shakeer Ahmed, a contract worker of the Nirmal municipality. 

Narayan Singh reportedly claimed that he and Shakeer had joined ISIS and received Rs 100 crore to carry out attacks.

The Nirmal police told TOI that Narayan Singh and Shakeer Ahmed did stay in the town, but were innocent government employees and the letter may have been written by someone who wanted to get them into trouble.