UN chief Ban Ki-moon joined countries across the world including the US, Russia, the UK, France, the UAE and Pakistan in condemning the terror strike in India's commercial hub.
"The members of the Security Council reaffirmed that terrorism in all its forms and manifestations constitutes one of the most serious threats to international peace and security, and that any acts of terrorism are criminal and unjustifiable, regardless of their motivation," said a statement read out by Peter Wittig, Germany's ambassador to the UN and current Council president.
The council expressed its deep sympathy and sincere condolences to the victims of these "heinous acts" and to their families, and to the people and Government of India.
A statement from the office of the UN chief said: "The Secretary-General (Ban) condemns the attacks that have killed and injured many in Mumbai.
"No cause or grievance can justify indiscriminate violence against civilians. The Secretary-General expresses his solidarity with the Government and people of India, and extends his sincere condolences to the families of the victims," it added.
In Washington, US President Barack Obama condemned as "outrageous" the attacks in Mumbai and offered support to bring the perpetrators of the "terrible crimes to justice".
"I strongly condemn the outrageous attacks in Mumbai," Obama said in a statement.
"India is a close friend and partner of the United States. The American people will stand with the Indian people in times of trial, and we will offer support to India's efforts to bring the perpetrators of these terrible crimes to justice," Obama said, recalling his visit to Mumbai last year.
US Secretary of State Hillary Clinton made it clear that she would go ahead with her visit to New Delhi next week for the security dialogue saying it is more important than ever to stand with India in the struggle against terrorism.
"We condemn the despicable act of violence designed to provoke fear and division. Those who perpetrated it must know they cannot succeed", she said.
Russian Foreign Minister Sergey Lavrov joined hands with Clinton in condemning the Mumbai blasts.
"We condemn the people who organized this act, and we extend our condolences to India and the Government of India," Lavrov told reporters at a joint media availability with Clinton at the Foggy Bottom headquarters of the State Department.
In London, British Foreign Secretary William Hague denounced as "deplorable acts of terrorism" the blasts in Mumbai, saying it is committed to working with the Indian government to combat the threat of terror in all forms.
"These were deplorable acts of terrorism. The UK stands firmly with India in the face of such atrocities. We are committed to working with the Indian government and our allies and partners to combat the threat from terrorism in all its forms," Hague said in a statement, adding a Foreign Office team was in Mumbai to support any British nationals there.
A statement by French President Nicolas Sarkozy's office described the attack as "cowardly and blind" while reaffirming its support for India in the fight against terrorism.
"As the city of Mumbai is again hit by a series of terrorist attacks, the president of the Republic firmly condemns the cowardly and blind violence and wants to express France's full solidarity with India's authorities in these painful hours," the statement said.
"More than ever France is standing by India in its fight against the scourge of terrorism," the statement added.
French Foreign Minister Alain Juppe earlier described the attacks as "barbaric" and said they evoked "horror and indignation".
UAE Foreign Minister Sheikh Abdullah bin Zayed Al Nahyan said in Dubai that "the UAE condemns this terrible, appalling crime and affirms its full solidarity and standing with the Government of India in confronting these criminal acts."
Pakistan President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani also condemned the blasts.
"President Asif Ali Zardari, Prime Minister Yousuf Raza Gilani, the government and the people of Pakistan have condemned the blasts in Mumbai and expressed distress on the loss of lives and injuries," said a statement issued by Foreign Office spokesperson Tehmina Janjua in Islamabad.
"The President and the Prime Minister have expressed their deepest sympathies to the Indian leadership on the loss of lives, injuries and damage to property in Mumbai," Janjua said.
Terror struck Mumbai last evening when three near simultaneous blasts ripped through crowded areas in the city. At least 21 people were killed and 141 injured.
Sri Lankan President Mahinda Rajapaksa "strongly condemned the cowardly terrorist attacks in Mumbai", presidential spokesman Bandula Jayasekera said in Colombo.
"President Rajapaksa condoles with the families, the government and the people of India," Jayasekera said.
German Chancellor Angela Merkel sharply condemned the attack and assured India that her country stood by its side in its fight against terror.
"It was with disgust that I received the news of the attacks in Mumbai," she said in a statement during a state visit to Angola.
"Ruthless persons resorting to brutal violence will not succeed in their efforts to take India out of its path of democracy and peaceful coexistence," she said.
Australian Prime Minister Julia Gillard also condemned the attacks, dubbing it as "senseless" attacks.
"We know their strength and are confident they will meet this latest challenge with courage and determination to stand against such senseless acts of violence," she said in a statement.
"Mumbai is a brave city that has already known great sorrow at the hands of terrorists, including in the 2008 attacks in which two Australians lost their lives," she said.
Earlier, Foreign Minister Kevin Rudd said such attacks had "no place in the civilised world".
Rudd said he was also confident Indian authorities would track down the perpetrators and bring them to justice.
"Australia stands in solidarity with India at this most traumatic time," he said.
