United States President George W Bush, United Nations chief Kofi Annan were among several world leaders who expressed outrage over the Mumbai bomb blasts and urged urgent coordinated action against the scourge of terrorism.
Sending his deep condolences to the friends and families of the victims of the "brutal attacks", Bush said the United States stood with India in the war on terrorism.
"The United States stands with the people and the Government of India and condemns in the strongest terms these atrocities, which were committed against innocent people as they went about their daily lives," Bush said in a statement on Tuesday.
"Such acts only strengthen the resolve of the international community to stand united against terrorism and to declare unequivocally that there is no justification for the vicious murder of innocent people," he said.
The UN Secretary General Kofi Annan has said that he was "appalled by the brutal and callous bombings" of trains in Mumbai.
He emphasised that such acts only confirm that terrorism constitutes one of the most serious threats to international peace and security.
In a statement issued through his spokesman, Annan said that the bombings in Mumbai and the grenade attacks in Srinagar "increase the urgency of coordinated action by all countries to defeat terrorism in all its forms and manifestations, committed by whomever, whenever, wherever and for what ever purpose".
Annan has extended his condolences to the Government and people of India, and "to all who have lost loved ones in this horrific slaughter."