New Delhi, April 2: The Election Commission is keeping strict vigil on the Bengal polls. After appointing special observers, it has decided to have “area superintendents” who will monitor polls in the state.

“These superintendents will keep watch over polling officers and will carry out random checking at the polling booths to prevent any tampering,” said an official. Referring to fears of “scientific rigging” by the Left Front, the official said the superintendents would monitor the “attitude” and functioning of political parties.

Trinamul Congress leader Mamata Banerjee had complained to the panel about the manipulation and intimidatory tactics used by the ruling CPM in Bengal. Subsequently, the commission issued an order that 50 per cent of polling officers in Bengal must be from outside the state.

Commission officials said tampering with electronic voting machines would be very difficult. “They are not in computer mode where you can programme the machine to function in a particular manner,” an official said.

The EVMs, he said, were machines without any programme or software. The machines can accommodate names of 16 candidates and their party symbols. Once a voter presses the button, a green signal comes on and there is a beep to indicate the vote has been registered.