India's Prime Minister, Dr Manmohan Singh, has said the country would not kneel to terrorism after yesterday's bomb attacks in which more than 183 people were killed and hundreds were injured.
Investigators in Mumbai have been examining the wreckage of trains and commuter railway stations following the explosions.
They said today they had prepared sketches of three suspects seen at some of the sites of the seven coordinated bomb blasts that killed at least 186 people.
As yet no group has claimed responsibility for the succession of near simultaneous explosions during the evening rush hour in the western Indian city, formerly known as Bombay.
Reports this morning said a timer device was found near one of the stations and an unexploded device may have been located.
The authorities say these could provide vital evidence about those behind the attacks.
Security has been tightened across India, but despite the bombings, millions of people packed trains and buses to get to work in India's biggest city today.
Police said high-grade explosive material was used in the blasts and tests are being carried out to determine the exact nature of the material used.
Pakistan denies involvement
Extra police have been deployed across the country to prevent possible communal retaliation as suspicion began to fall on Islamist militants fighting Indian rule in part of the disputed Kashmir region.
Pakistan denies supporting the militants and condemned what it called the 'terrorist attack' in Mumbai.
However, India took offence at comments from Pakistani Foreign Minister Khursheed Mehmood Kasuri, who said that the two countries could only cooperate to fight extremism if they resolved outstanding disputes such as Kashmir.
The death toll was the worst since a series of bombs killed more than 250 in Mumbai in 1993. The attacks were also eerily reminiscent of serial bomb blasts on commuter rail networks in Madrid and London in the past two years.
Taoiseach condemns attacks
The Taoiseach, Bertie Ahern, has condemned the bomb attacks.
Writing to the Indian Prime Minister the Taoiseach stressed that these shocking atrocities are to be utterly condemned.
Mr Ahern said: 'We stand in full solidarity with the government and people of India as you deal with such appalling and contemptible acts.'
