Roopa Ganguly and other BJP leaders were today stopped near the Kolkata airport as they attempted to visit Basirhat, where violence erupted again yesterday after a police lathicharge. Teams from the Congress and the Left were asked to turn back too by the police, which has barricaded Basirhat, about 100 km from state capital Kolkata. The opposition parties said they were going to the town to appeal for calm; Chief Minister Mamata Banerjee has requested them to keep away, promising that no leader from her Trinamool Congress will go there either.