Indian Prime Minister Manmohan Singh says the bombers behind the deadly train blasts in Mumbai were "supported by elements across the border."
Mr. Singh, who is visiting Mumbai (formerly known as Bombay), said Friday that Pakistan must rein in terrorists on its soil before the peace process can continue.
The prime minister plans to meet with survivors undergoing treatment in local hospitals. He is also expected to meet with officials investigating Tuesday's attacks in Mumbai.
In another development, officials in Nepal say they are investigating two Pakistanis for possible links to the railway bombings.
Authorities say the two men were arrested Tuesday at a Kathmandu hotel. They were detained in connection with the discovery of powerful explosives in Kathmandu in 2001.
A Nepalese court granted police five days to interrogate the Pakistanis about the Bombay train bombings, which killed about 200 people and wounded 700 others.
Pakistan's Foreign Ministry has dismissed allegations in the Indian media that Pakistani intelligence agents were involved in the attacks, calling the accusations "frivolous".
New Delhi television has reported that police are investigating phone calls made to Dubai and the Pakistani city of Karachi minutes before and after the blasts.
Indian authorities are searching for three suspects in the coordinated bombings, including a terrorist mastermind named Rahil. The other two suspects were named as Sayyad Zabiuddin and Zulfeqar Fayyaz.
Indian officials said Thursday the prime suspect in the bombings is Lashkar-e-Toiba, an outlawed Pakistan-based Islamic militant group that operates in Indian Kashmir. Lashkar denies it was involved.
Some information for this report was provided by AFP, AP and Reuters.