The other blasts took place near near Elphinston cinema and Twins Tower, close to Gandhi Maidan, the venue of the rally.
The first blast took place at Patna railway station at 11 am
The BJP and the RJD condemned the blasts. While the BJP said a probe was on to find out who is behind the blast, the RJD slammed the Nitish Kumar administration, saying it was a security lapse.
Patna police said the bomb disposal squad was conducting a search.
A seven-member team comprising of NIA and NSG personnel went to Patna to investigate the blasts. The home ministry sough a report from the state government. Prime Minister Manmohan Singh condemned the blasts too and spoke to Bihar Chief Minister Nitish Kumar over the phone.
Kumar was not in Patna during the day.