Pakistan on Friday said reports that Indian police are tracing telephone calls to Pakistan and Bangladesh following the Mumbai train bombings was "frivolous".
But the Foreign Office reiterated President Pervez Musharraf's offer to support the probe into Tuesday's coordinated attacks on Mumbai, which killed over 200 people.
"These reports or charges are simply frivolous," Foreign Office spokeswoman Tasnim Aslam said.
An Indian daily reported that a telephone call traced by intelligence services from the southern Pakistani city of Karachi to the Bangladeshi capital Dhaka said "congratulations".
Another caller contacted his mother in Karachi from a public call box saying he was fine but could not disclose his location -- and swiftly hung up, it said.
Pakistan was ready to cooperate with the investigation if India would share information and evidence, said Aslam.
"Our stand is what President Pervez Musharraf has already said -- that we would support India's probe into the bomb blasts," he said.
A senior police official in Karachi said they were ready to look into the telephone calls if necessary.
"If someone has contacted his mother in Karachi from Mumbai after the bomb blast saying he is fine, it's nothing but natural. If there is anything else we are ready to help," he said on condition of anonymity.