Of the over hundred cyber cafes in Salt Lake, only 13 are legal, Bidhannagar Municipality said on Monday after surveying the mushrooming Internet parlours in the township.

“All other cyber cafes in Salt Lake are illegal in the sense that they either do not have a trade licence or their licences have expired,” said Asoke Das, the sub-divisional officer of Bidhannagar. “I will ask the cops to take necessary action against the owners of illegal cyber cafes.”

The list includes cyber cafes in IA, EC, BK, BE, AE, BJ, HB, DL, BG, BH, IB, HA and BF blocks.

The district magistrate has issued an order that all cyber cafe owners in North 24-Parganas must follow guidelines. The order also says that if any cyber cafe owner ignores the guidelines, he may be imprisoned up to six months or fined up to Rs 1,000.

“The order empowers us to crack down on illegal cafes in Salt Lake. We can also book the legal ones if they violate norms,” said Ashoke Biswas, the additional superintendent of police, North 24-Parganas.