At least 80 people have died in a series of bomb blasts which ripped through the crowded streets of India's western city of Jaipur.

Police say seven bombs, many strapped to bicycles, exploded within minutes of each other inside Jaipur's old walled city on Tuesday evening.

The blasts targeted busy markets and Hindu temples, leaving hundreds injured and overwhelming city hospitals.

No one has yet claimed responsibility for India's deadliest bomb attacks in nearly two years.

But within hours of the blasts, authorities were hinting that the blame could fall on Pakistan-based groups that India accuses its neighbor and rival of backing.

"Obviously, it's a terrorist'' attack, said A.S. Gill, the police chief of Rajasthan, the state where Jaipur is located.

"The way it has been done, the attempt was to cause the maximum damage to human life."

An eighth bomb failed to explode and was defused by police.

Al Jazeera correspondent Matt McClure, who is in Jaipur, said building and shop signs around one of the attack sites were pockmarked with holes from ballbearings that police say were packed into the bombs.

He said there were large numbers of police deployed on the streets of the city following the attacks amid fears there could be a backlash against the city's Muslim minority.

'State of terror'

Ashok Parnami, the city's mayor, said Jaipur had been placed in "a state of terror" by the attacks.

One bomb went off at a market near a temple dedicated to the Hindu monkey god Hanuman.

Tuesday is the day of worship set aside for Hanuman, and the temple was crowded with people offering prayers on their way home from work.

Another bomb detonated near the Johari Bazaar, the city's jewellery market and a popular tourist destination.

May is considered low season for the city's tourism industry, however, and there were no immediate indication that foreigners had been caught in any of the explosions.

"One can't rule out the involvement of a foreign power," said Sriprakash Jaiswal, India's junior home minister, using language commonly understood to refer to Pakistan.

He refused to say if he was talking about Pakistan, but said "the blasts are part of a big conspiracy".

Pranab Mukherjee, India's foreign minister, is due to visit Pakistan in just over a week to review the four-year-old peace process.

His trip will be his first since a new, civilian government took over in Pakistan.

Indian authorities have blamed Pakistan-based groups for a spate of bombings that have killed nearly 400 people since 2005.

Pakistan denies any role in the bombings.

Indian authorities stepped up security at airports and railway stations across the country after Tuesday's attacks.

PHOTO CAPTION 

The site of a blast in Jaipur, India, Tuesday, May 13, 2008.

Al-Jazeera