"We condemn the despicable act of violence designed to provoke fear and division. Those who perpetrated it must know they cannot succeed," she said last night, shortly after the blasts rocked the financial hub of India.
Reaching out to India, Clinton said she would be travelling to the country next week on July 19-20 as planned.
"I believe it is more important than ever that we stand with India, deepen our partnership and reiterate our commitment to the shared struggle against terrorism."
She said the Indian people have suffered from acts of terrorism before and "we have seen them responding with courage and resilience. We are continuing to monitor the situation, including the safety and security of American citizens".
"We reach out to the Indian government to express our condolence and offer support", she added.
"Our hearts are with the victims and their families," Clinton said.
US Under Secretary of State for Political Affairs Bill Burns called Foreign Secretary Nirupama Rao to offer condolences and support following the Mumbai blasts.
"Under Secretary Burns did speak ... with Foreign Secretary Rao to convey our condolences and to offer our support, and (it is) worth noting as well that Secretary Clinton will have an opportunity to reaffirm our commitment to the US-India partnership when she travels there next week," State Department spokesperson Mark Toner told reporters after the Mumbai blasts.
"The US government condemns this senseless violence in the strongest possible terms. We offer our condolences to the families and friends of those affected by this attack and stand in solidarity with the people of India and Mumbai.
"We offer our full support and assistance to the government of India in their response to and investigation of the attack," Toner said.