Calcutta, Aug. 10: Umbrellas were the first casualties in the police crackdown on Salt Lake’s Banabitan, from where 50 people were arrested yesterday on the charge of “immorality”.

The reason for the bar: “shady” activities can be carried out under its shade.

The police, however, insisted that there was nothing new in the move. “Such a rule had been introduced by the forest department under whose purview the park falls,” said Ashok Biswas, the additional superintendent, Salt Lake. “All we are saying is that this rule should be enforced for the benefit of all.”

The police said many people were taking advantage of the park’s green cover to indulge in “immoral activities” and that call girls were brought there from faraway places.

A forest official confirmed the ban on umbrellas in the park. “We had banned umbrellas in the park in May 2005,” the official said. “As it is, there is a shortage of guards. On top of it, if umbrellas are allowed, a lot of nefarious activities can be carried out.”

The official conceded that the earlier ban was “not strictly enforced”.

Police said people often took pictures of couples in compromising positions on cellphones and circulated them. “We want to prevent this kind of activity, which was increasing,” Biswas said.

Those arrested were released today on bail. In many cases, the guardians were called to the police station. “All of them had to give a written undertaking that they would not indulge in obscene acts in the future,” Biswas said.