July 12 (Bloomberg) -- India's Prime Minister Manmohan Singh pledged to tackle terrorism with ``all possible measures'' as governments across the world condemned the worst bomb attacks in Mumbai in 13 years. At least 183 people were killed.

``We will work to defeat the evil designs of terrorists and will not allow them to succeed,'' Singh said yesterday after eight blasts on the suburban rail network in the country's commercial hub. The bombs injured at least 663 people.

Eight explosions occurred within 30 minutes starting at 6 p.m., ripping through rush-hour crowds in the city of 16 million. Much of the rail network was suspended and phone services disrupted. The Lashkar-e-Taiba terrorist group, which seeks an end to Indian control of Jammu and Kashmir state, claimed responsibility, according to the CNN-IBN television channel.

``Such acts only strengthen the resolve of the international community to stand united against terrorism,'' U.S. President George W. Bush said in a statement. The U.S. condemns ``these atrocities'' in the strongest terms, he said.

Britain will ``stand united with India'' in a ``shared determination to defeat terrorism,'' Prime Minister Tony Blair said in a statement. ``The terrorists to blame for carrying out this evil act must receive the harshest punishment,'' Russian President Vladimir Putin said.

Kashmir Separatists

India accuses Pakistan of backing separatist groups fighting in Jammu and Kashmir, India's only Muslim majority state, and allowing them to cross the border. Pakistan has denied this, saying it only lends moral support to a freedom struggle. The South Asian neighbors, after fighting three wars, have improved ties since April 2003 by restoring diplomatic and transport links.

Pakistan President Pervez Musharraf and Prime Minister Shaukat Aziz issued a statement condemning the attacks.

``There will be a strong reaction from New Delhi,'' said M.J. Gohel, a terrorism analyst with the Asia Pacific Foundation, a London-based research institute. ``The government will be under enormous pressure to act.''

Activists from both Lashkar and the Students Islamic Movement of India may have been behind the attacks, the Times of India reported today, citing intelligence sources who have been tracking increased links between the two groups. The attacks were aimed at triggering communal riots, the paper said.

``As of now we have no information on who is responsible,'' said Arun Patnaik, joint police commissioner in Mumbai. The Prime Minister's Office today declined to immediately comment on who may be responsible.

`Global Jihad'

``India is very much a target of global jihad,'' or holy war, Gohel said. The incident may cause ``some cooling in relations with Pakistan,'' which he said ``has not been doing enough to stop'' terrorist groups.

The Indian authorities put major cities and airports on alert, stepping up security patrols in public places. In the U.S., New York City police increased anti-terrorism patrols and kept hundreds of officers on duty to step up inspections of backpacks and containers at subway stations.

U.S. Homeland Security Secretary Michael Chertoff said in a statement the department is ``closely monitoring'' the Mumbai developments. He said there was no evidence of an imminent threat to the U.S. and no plans to raise the country's alert level.

Earlier yesterday, grenade attacks by suspected Islamic terrorists killed eight people in Srinagar, the summer capital of Jammu and Kashmir, situated in the northern part of the country.

Car Bombings

The Mumbai attacks were the worst by terrorists in the city since almost 200 people died in a series of blasts in 1993 that targeted the Bombay Stock Exchange and other commercial landmarks. On Aug. 25, 2003, more than 40 people died and 124 were injured in car bombings in a crowded market in southern Mumbai and outside the Taj Mahal Palace hotel.

``Apart from the fact that the attacks were carried out in the financial capital, Mumbai, the real economic impact is limited'' in comparison to the aftermath of the Sept. 11 attacks on the U.S., said Amitabh Dubey, a South Asia analyst at risk consulting firm Eurasia Group. ``Indians are a little more resilient to this kind of violence.''

Mumbai, on India's west coast, is home to the country's biggest equity and money markets, the central bank, companies such as Reliance Industries Ltd. and the country's busiest airport.

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

The latest attacks are ``certainly going to have some impact on the government,'' Dubey said. ``It's already under attack from opposition parties who accuse it of being soft on terrorism.''

Relief Measures

Sonia Gandhi, president of the federal ruling Congress Party, asked the Maharashtra state government to undertake relief measures and apprehend the culprits immediately. Maharashtra is ruled by a coalition government led by the Congress Party. She appealed for people to ``collectively isolate such elements from society,'' the Congress Party said in a statement.

Gandhi and Home Minister Shivraj Patil were planning to visit Mumbai.

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

London's public-transportation system was rocked by attacks last year. Four suicide bombers killed 52 people and injured more than 700 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.

`Called to Account'

German Foreign Minister Frank-Walter Steinmeier said in an e-mailed statement that those responsible for the Mumbai attacks, ``who have made so many innocent civilians their targets of futile violence, have to be found as soon as possible and called to account.''

South African President Thabo Mbeki expressed ``confidence that the Indian authorities will ensure that those responsible will face the consequences of their own actions,'' Mbeki said in a message to Indian President Abdul Kalam, issued by the department of foreign affairs.

Kalam is scheduled to visit Mumbai next week and Jammu and Kashmir at the end of this month, Press Trust of India said.

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.

To contact the reporters on this story: Kartik Goyal in New Delhi at kgoyal@bloomberg.net; Bibhudatta Pradhan in New Delhi at bpradhan@bloomberg.net.

Last Updated: July 11, 2006 23:57 EDT