One woman was killed and 25 persons injured on Monday evening in a blast near Vile Parle station in suburban Mumbai.
Police Commissioner R S Sharma said an explosive appeared to have been placed on a bicycle, which was found completely destroyed, parked in the busy market place just outside on the eastern side of the station.
Most of the victims suffered minor injuries, he said. The injured have been taken to the Cooper and Nanavati hospitals nearby.
In view of this incident, which comes a day before Prime Minister Atal Bihari Vajpayee's visit to the city, Sharma said security would be stepped up.
Police also dismissed as rumours reports that some explosive material has been seized from Malad, Thane and Ghatkopar.
Sharma later visited the nearby Cooper Hospital, where he told reporters that two seriously injured persons have been shifted to the KEM Hospital in south Mumbai.
With inputs from PTI