In an effort to curb prisoners in Kalapet jail from using mobiles to carry out illegal activities through their associates outside, Revenue officials have sealed five mobile towers in the vicinity of the prison as the towers make jammers in the central prison ineffective. Though representatives of service providers made frantic efforts to stop the sealing operation citing the possibility of signal disturbance to mobile users, revenue officials went ahead with the operation.

Speaking to The Hindu , S.B. Deepak Kumar, Collector-cum-District Magistrate, said on Wednesday that the towers were sealed under Section 133 of Cr.P.C. that empowered the District Magistrate to pass an order for removal of nuisance.

The action was taken following complaints that the towers were emitting high levels of radiation and as they were functioning with wider frequencies, jammers fitted in the jail could not disable cell phone usage inside the prison.

Mr. Kumar said he had received information that the mobile towers used by service provides such as BSNL, Aircel, Airtel, Tata Docomo, Vodafone, Idea and Reliance had switched off their operation immediately after the sealing operation. The officials were asked to closely monitor the developments.

A few days ago, the Lieutenant Governor Virendra Kataria had made a sudden visit to the prison following complaints that prisoners had been threatening traders and businessmen through mobile phones demanding ransom. He also checked the functioning of three jammers installed on the premises.

Mr. Kataria was told by prison authorities that jammers could not disable mobile phone signals owing to the transmission of signal with wider frequencies by the towers installed close to the jail.