Indian authorities identified two suspects in the co-ordinated attack on Mumbai's commuter train network that killed at least 200 people and wounded more than 700.

The government's Anti-Terror Squad released photos on Thursday of two young, bearded men identified as Sayyad Zabiuddin and Zulfeqar Fayyaz. Authorities did not release the nationalities of the men.

Police earlier detained about 350 people overnight for questioning.

Police Inspector S. Goshal told The Associated Press most of the detentions were made overnight in Malwani, a northeastern suburb of the bustling metropolis.

Those detained were described as known thugs and gangsters who may be able to provide authorities with information about the guilty parties.

There are also unconfirmed reports that most of those detained are activists from the Students' Islamic Movement of India, a group banned in 2001 for allegedly trying to provoke unrest over the U.S.-led war on terror.

Meanwhile, the bustling city of 16 million was back on track Thursday with tens of thousands of people cramming the commuter train service.

On Tuesday, the commercial capital of India was rocked by eight near-simultaneous bombs at evening-rush hour, killing at least 200 people and wounding more than 700.

Authorities are continuing to comb through the wreckage for clues, but early indications signal electrical timers could have been used to set off the bombs.

"We can be sure only after the forensic and ballistic results, but so far it looks like crude electrical timers were used," a senior Mumbai police officer told Reuters.

Suspicion has turned to Muslim militants fighting New Delhi's rule in disputed Kashmir, who have employed near-simultaneous blasts to attack Indian cities in the past.

Investigators are investigating a possible link with Lashkar-e-Tayyaba. But the Kashmir-based Islamic militant group has denied any involvement.

Lashkar has in the past employed near-simultaneous explosions to attack Indian cities.

The overnight detentions came as a man claiming to represent al Qaeda claimed the terror network had set up a wing in Kashmir and praised Tuesday's bombings.

The purported al Qaeda member urged Indian Muslims to take up jihad and said "whosoever has carried out the attacks in Mumbai we express our gratitude and happiness." Neither the man's identity nor claims were authenticated.

The bombings "are a reaction to what is happening to the minorities, especially Muslims in India," the man said in a statement read over the phone to Kashmir's Current News Service.

"We appeal to Muslims in India to fight for freedom and Islam and choose jihad as their way to achieve freedom and establishing Islamic ways," he was quoted as saying in Urdu, the language of most Muslims in the Indian subcontinent, though he identified himself with the Arabic name of Abu al-Hadeed.

"Today a unit of al Qaeda has been established in Jammu and Kashmir which shall henceforth be called al Qaeda Jammu and Kashmir," the man said.

He added that the purported al Qaeda wing will be releasing regular statements and will soon announce its objectives.

A senior intelligence official told AP that authorities were trying to trace the man's phone call.

"Our immediate effort is to locate the caller and ascertain the authenticity of the claim," the official said on condition of anonymity. "The government is taking it very seriously."

There have been charges that Islamic militants fighting to take control of Kashmiri territory are linked to al Qaeda, but Thursday's statement would be the first time the terror network claimed to have planted roots in the Indian territory.

Meanwhile, the government renewed its vow to stamp out terrorism.

"Nothing will deter us from our firm policy to fight this menace till it is wiped out. We are determined to apprehend and bring to justice all those responsible for the evil acts in Mumbai," said a Cabinet statement.

The Indian Foreign Ministry demanded Wednesday that neighbouring rival Pakistan take action against terrorist networks operating on land it controls -- but fell short of directly accusing it for the attacks.

Kashmir has been split between Hindu-dominated India and Muslim-dominated Pakistan after the two nuclear rivals gained independence from Britain in 1947, but both claim it in full.

In an interview with AP in Washington, Pakistan's foreign minister rejected suggestions his country was responsible for the bombings.

"You can't really blame everything on Pakistan; it's very unfair," Khurshid Kasuri said. "India is a vast country. There are lots of people who have their own agendas, not just in Kashmir."

With files from The Associated Press