Fifteen fishermen, who put to sea from here, were today attacked allegedly by Sri Lankan Navy when they were fishing near Dhanuskodi, fisheries department sources said. The fishermen were fishing near a sand hillock in Indian waters when the Lankan Navy came in two boats and allegedly beat them up with sticks, said Plavumin Thiyakarajan, Assistant Director, Fisheries department. The Lankan navy personnel told them they were fishing in Lankan waters and sent them back with a warning, officials said.