Maharashtra Home Minister R R Patil reviewed security situation with senior officials on Wednesday night, following the four low-intensity explosions in Pune.
The explosions came over two years after the bomb blast at German Bakery in Pune, which killed 17 people and injured 64 at Koregaon park on February 13, 2010.
Patil discussed the situation with top home department officials, sources said. An alert has been issued following the explosions, which come a day ahead of the Raksha Bandhan festivities.
A strict vigil will be maintained at crowded places like railway and bus stations, malls, markets and lodges, a home department official said.
Explosions in Pune occurred near Balgandharva Theatre, at a Dena Bank branch and a McDonalds joint, while another explosion was reported in a dustbin in the area.