July 12 (Bloomberg) -- Mumbai, India's commercial hub, was rocked by eight explosions at seven sites on trains and in commuter stations yesterday, killing at least 173 people and injuring 490 in the nation's worst terrorist attack in 13 years.

The explosions occurred within 30 minutes starting at 6 p.m., tearing apart train cars and ripping through rush-hour crowds in this city of 16 million. Mumbai police commissioner A.N. Roy said in a televised interview that much of the rail network was suspended and phone services were disrupted.

The Lashkar-e-Taiba terrorist group, which seeks an end to Indian control of Jammu & Kashmir state, may have been behind the attack, according to CNN-IBN television channel. India put all its major cities on alert after the blasts, the worst since almost 200 people died in 1993 attacks on the Bombay Stock Exchange and commercial landmarks. Mumbai is home to India's biggest equity and money markets, the central bank, companies such as Reliance Industries Ltd. and the country's busiest airport.

The blasts ``are shocking and cowardly attempts to spread a feeling of fear and terror among our citizens,'' Prime Minister Manmohan Singh said in New Delhi. ``I reiterate our commitment to fighting terror in all its forms.''

The Bombay Stock Exchange, home to the nation's benchmark index, will operate as usual today, Kalyan Bose, corporate director, said in a phone interview. The central bank will function normally today, said Rakesh Mohan, deputy governor of the Reserve Bank of India.

Eight Blasts, Seven Sites

The eight blasts occurred at seven locations, said M.K. Bhoye, an under secretary in the state government's general administration department, who also provided the casualty figure. The government previously said seven blasts had taken place.

``All the bombs were placed in the first-class compartments of the trains,'' said Shiv Charan, a police spokesman. It's difficult to say where in the compartments the bombs were placed, the official said.

The attacks hit Khar, Mahim, Mira Road, Jogeshwari, Borivali, Matunga and Bandra, Roy said. Early rescue attempts were hampered by monsoon rains, the Aaj Tak channel said.

The Mumbai explosions followed grenade attacks earlier yesterday by suspected Islamic terrorists that killed eight people in Srinagar, the summer capital of India's northern state of Jammu and Kashmir.

``There is no political cause that can justify the murder of innocent people,'' U.S. Secretary of State Condoleezza Rice said in a statement. The U.S. ``stands with India in the war against terror. Those responsible for these terrible acts should be swiftly brought to justice.''

Inspections

In New York City, which has been on alert since the Sept. 11 destruction of the World Trade Center, the police department held over its second shift to increase patrols in the subways with hundreds of officers. Mayor Michael Bloomberg said police would step up inspections of backpacks and containers on subway platforms and dispatch emergency vehicles to transit hubs.

``We have no information suggesting NYC is a target,'' Bloomberg said. ``Still, we take a terror attack anyplace in the world, especially one involving a public transportation system, as a serious warning.'' The mayor is founder and majority owner of Bloomberg News parent Bloomberg LP.

Schools, colleges and government offices will be open today, Maharashtra Chief Minister Vilasrao Deshmukh was cited as saying by Press Trust of India.

Commercial Hub

Mumbai generates about 5 percent of India's gross domestic product and contributes more than one-third of the country's tax revenue, according to the Mumbai Metropolitan Region Development Authority. More than 10 million daily passenger trips are provided by the suburban railway and the state-run bus service, according to the authority. Parts of the rail network were shut yesterday evening.

``Our priority now is to ensure that every injured person gets prompt treatment,'' Johny Joseph, Mumbai's municipal commissioner, said in a phone interview.

The arterial highways along the length of the island-city were crowded with people seeking to get to their homes in the suburbs from downtown Mumbai, Chief Fire Officer A.D. Jhandwal said in a phone interview. Emergency wards in hospitals near the blast sites are crowded with casualties, he said.

Television pictures showed people streaming with blood from the injuries being carried from railway coaches that had been ripped apart by the impact of the blasts. In at least one such instance, the metal roof of the railway platform was pulled off its moorings by the force of the blast. Appeals for blood donation were broadcast on television stations.

New Delhi, the capital, was rocked by three blasts Oct. 29 last year that killed at least 59 people in crowded market areas.

Target Cities

Since the Sept. 11 attacks on New York and Washington that killed about 3,000 people, terrorists linked to al-Qaeda have targeted cities around the world, including London and Madrid.

London's public-transportation system was rocked by two attacks last year. Four suicide bombers killed 52 people on July 7 on three subway trains and a bus. Two weeks later, bombers targeted three trains and a bus. Their explosives failed to detonate.

Train bombings in Madrid on March 11, 2004, killed 191 people and injured more than 1,500. In statements posted on the Internet, groups linked to al-Qaeda claimed responsibility for the London suicide bombings and the Madrid attacks.

The airport at Mumbai, India's busiest, has been put on ``high alert,'' Praful Patel, India's civil aviation minister, said in a phone interview. ``We have to remain alert. Security is being tightened all over,'' Patel said.

To contact the reporters on this story: Ashok Bhattacharjee in New Delhi at ashokb@bloomberg.net; Anand Krishnamoorthy in New Delhi at anandk@bloomberg.net.

Last Updated: July 11, 2006 17:13 EDT