Strongly condemning the Boston bomb blasts, Prime Minister Manmohan Singh on Tuesday wrote to American President Barack Obama expressing solidarity with the American people in the wake of the "senseless and cowardly act".
He said it was a "tragic reminder" that the evil of terrorism that still threatened the United States and India and "lurks in our cities".
"The people of India join me in condemning the attack in the strongest terms. We stand in solidarity and sympathy with the bereaved families, the injured and the people of the United States," he said expressing shock and sadness over the attack.
Dr Singh also offered full support to the US in the investigations into the attack.
He said the outrageous terror act has redoubled the resolve to remain unrelenting in efforts to defeat terrorism and defend and uphold values that define the two nations.
At least two persons were killed and 23 others injured in two blasts near the finish line of the annual Boston marathon on Monday.