Taking charge as Foreign Secretary, Shiv Shankar Menon rubbished Islamabad's denial of involvement of ISI and Lashker-e-Tayiba in Mumbai train bombings and said India wants Pakistan to "not only talk but act also".

"We will take up the issue (of involvement in Mumbai blasts) with Pakistan in view of the new evidence," he told reporters here, a day after Mumbai Police said its investigations had proved that the serial blasts which killed nearly 180 people and injured over 800 were planned by ISI and carried out by LeT.

Menon, who was High Commissioner to Pakistan before his ppointment as Foreign Secretary, said India would provide evidence with regard to the Mumbai blasts to Islamabad and see what it does to act on it.

On Saturday, Mumbai Police Commissioner A N Roy, while claiming to have cracked the case, said ISI's involvement had clearly emerged in investigations.

He said the terrorists who had carried out the blasts included Pakistanis sent to India in batches via Nepal, Bangladesh and Gujarat especially to carry out the nefarious task.

The Pakistan Foreign Office had immediately rejected Mumbai Police's claim, which, it said, was "unsubstantiated" and "baseless".

Menon, a 1972 batch IFS officer, succeeded Shyam Saran who has retired.

Saran has been appointed Special Envoy on negotiations with regard to the Indo-US civil nuclear deal.

On the fate of the nuclear deal, the new Foreign Secretary said it enjoys bipartisan support in the US Congress and hoped for early passage of a bill that will pave the way for resumption of civil nuclear trade with India.