At least six persons were injured in two blasts -- in Jalna and Parbhani -- in Marathwada region of Maharashtra on Friday.
The blasts took place in mosques. Sources said motorcycle borne miscreants lobbed crude bombs into the mosques.
Joint Commissioner of Police (Law and Order) Ahmed Javed in Mumbai confirmed the blasts and said an alert has been sounded in the metropolis.
"I have already spoken to officers and given necessary instructions to take precautionary measures," he said.
Police have been deployed at places of worship and sensitive ares in the city and patrolling has been stepped up.
The anti-riot police have been asked to remain ready for any eventuality.