At least 15 people were killed and 100 injured as up to 16 synchronised bombings rocked busy areas in India's western city of Ahmedabad on Saturday, officials said, dpa reported.
The low-intensity blasts occurred within 45 minutes starting at 6.45 pm (1315 GMT) local time in Ahmedabad, which is among the top commercial cities in India, triggering panic amongst the locals.
The explosions took place in the Maninagar, Isanpur, Bapunagar, Hatkeshwar, Sarangpur, Sarkhej, Narol circle and Odhav areas in the key city located in Gujarat state.
"According to my information, at least 15 people have died. Over 100 have been injured," Gujarat Urban Development Minister Nitin Patel told reporters.
"At this time our priority is to maintain law and order and rescue people," Patel added.
The blasts come a day after eight low-intensity bombs hit the southern city of Bangalore, claiming two lives.
The bombs appear to have been planted on bicycles or in tiffin boxes and were triggered by timer devices, state police officials said.
Even though these were low-intensity blasts, the number of casualties was high and likely to rise as the attacks occurred in crowded marketplaces and areas which have a large population of migrant workers.
"The bombings have been well-coordinated as some explosions were also reported from hospitals and trauma centres where the injured were being moved," a police official said requesting anonymity.
There was complete chaos at the blast sites as crying and screaming people ran for safety, leading to a near stampede in the congested areas.
Charred and mangled remains of a bus, motorcycles and bicycles could be seen at the blast sites as medics rushed dozens of wounded to hospitals, leaving trails of blood on the streets.
In Bapunagar, the blast shattered the windows of a bus and ripped off its roof. Policemen tried to gather debris and remnants from the crude bombs for forensic analysis.
Tension was palpable in the city as police erected barricades to check vehicles in the areas.
Indian leaders including President Pratibha Patil condemned the blasts and asked people to maintain peace and communal harmony.
Police expressed fears that the bombings could trigger sectarian clashes in Gujarat, which has witnessed large-scale riots between Hindus and Muslims in the past.
Over 1,000 people, most of them Muslims, were killed in Hindu-Muslim riots in Gujarat in 2002.
Additional police forces were dispatched to the sensitive areas to maintain law and order. Security forces sealed the Ahmedabad railway station and tightened security around the airport.
In Delhi, India's junior Home Minister Sri Prakash Jaiswal said preliminary investigations indicated that the blasts seemed to be similar to the terrorist bombings in Bangalore on Friday.
"It is a conspiracy to unsettle the country," Jaiswal said adding, "All the metropolitan cities in the country have been placed on high alert."