Calcutta, Aug. 6: Rrrring: blasts are out. Singur is in.

An anonymous caller has apparently threatened to “kill” Mamata Banerjee if she laid siege to the Tata Motors plant in Singur, dipping into the arsenal of panic-mongers who have been driving police up the wall since the Ahmedabad blasts.

Trinamul Congress leader Partha Chatterjee said the party chief got the call last evening on her landline phone in her Kalighat home.

The caller spoke in Bengali, warning her that if she proceeded with her indefinite dharna at the project site in Singur she would be killed, Chatterjee said today.

The call came around 8pm and Mamata herself took it. The caller hung up when she raised the alarm.

Ten minutes later, Mamata got an SMS saying: “If Tatas withdraw from Singur, let’s ensure TMC’s exit from planet earth,’’ Chatterjee quoted the SMS at a news conference.

Through the day, Mamata did not drop any hint that would appease the caller but she did strike a blow for development.

In a letter to the Prime Minister, she sought his intervention to dredge the Haldia dock immediately, without which it would become “useless”.

Mamata, who stayed away from the trust vote and indirectly helped the UPA government, must be expecting a positive response from the Prime Minister, unlike the Left which is fearing a go-slow.

Asked if a police complaint was lodged, Chatterjee said: “We have lodged a complaint with the appropriate authority.” But Jawed Shamim, the deputy commissioner, detective department, said the police were yet to get a formal complaint.

Raj Kanojia, inspector-general, law and order, said the CID received an anonymous call last night informing them about the threat call. “So, the investigating agency was asked to initiate a probe.” Calcutta police are also probing the matter.