The tanker caught fire following an accident and exploded causing fiery balls of the chemical to fall on the motorists travelling on the road below, an official said

Maharashtra Deputy Chief Minister Devendra Fadnavis expressed grief over the deaths. Fadnavis, who also holds the home portfolio, called the accident "unfortunate"

Four motorists on the road below sustained injuries, of which three died, while one occupant of the tanker was killed and two others in the vehicle were injured, said the official from Lonavala police station

"It is very unfortunate that 4 people died in an accident on the Mumbai-Pune highway. I pay my heartfelt tribute to them. 3 people were injured in this incident and they are undergoing treatment in a hospital. I pray to God that they recover soon," Fadnavis wrote on Twitter

The state police, highway police, personnel from INS Shivaji and the fire brigade are at the spot and the fire has been brought under control, Fadnavis said. The traffic from one side of the highway has resumed. Another side will be opened soon. The situation is being monitored by the state, he added