Power supply to eight plastic warehouses and processing units built illegally inside the East Kolkata Wetlands were cut off by the authorities on Thursday.

There are hundreds of cases of unauthorised construction and illegal conversion of the nature of land inside the notified East Kolkata Wetlands area, but authorities have acted against only a handful till now.

The East Kolkata Wetlands Management Authority has filed more than 500 FIRs against such illegal acts, said an official of the state environment department.

“Power supply to these units were snapped. This was done as per orders of Calcutta High Court,” said a senior official of the state environment department.

“We asked the owners to stop operations and move out, but they did not do so. When they did not comply with the direction, we snapped the power supply,” said the official.

It was not clear whether the authorities would also pull down the structures.

An official of the department said that out of the 500 FIRs filed with police, the wetlands authority has also issued demolition orders on their own in some cases.

“In cases where we found that the structures were built illegally, we have already passed demolition orders,” he said.

The East Kolkata Wetlands, a Ramsar site, has three parts — settlements (where human habitation is allowed), agricultural land and water bodies. Conversion of water bodies into agricultural land or plots for human habitation is banned.

The eight units where the power supply was cut off also moulded the raw plastic. In the process they also emitted a lot of foul smoke and polluted the air, said an official.