Four persons, including a woman and 3 men died in a police firing on agitated mob in Mawal Tehsil of Pune District on Tuesday. Farmers and locals from the Mawal area were demonstrating against the proposed water pipeline from Pawna dam demanding that the water be supplied only for agricultural purposes. Police sources said, the agitators tried to block rail traffic on Pune-Mumbai route and also blocked Pune-Mumbai Expressway at Talegaon and Lonavala.Police had to resort to firing to disperse the agitators at Baur in which four persons died and several others injured. The enraged mob pelted stones on the police and set some vehicles on fire. Around one hundred people have been taken into custody and the situation in the area is now under control, said police sources. The Pune-Mumbai Expressway has been cleared for traffic again.