India on Dec. 22 gave Pakistan a letter written by Ajmal Qasab, the only gunman captured after the November attacks in Mumbai. Qasab wrote that he and the nine other gunmen involved in the Nov. 26-29 rampage all came from Pakistan, India's Foreign Ministry said. He also requested a meeting with Pakistani envoys, the ministry said.

Islamabad has not acknowledged that Qasab is Pakistani and has said it is waiting for proof of his citizenship before it will take further action.

Indian Foreign Minister Pranab Mukherjee said that if Pakistan doesn't deal with those responsible, India was prepared to "take all measures necessary as we deem fit to deal with the situation." He did not elaborate.

"Unfortunately, Pakistan's response so far has demonstrated its earlier tendency to resort to a policy of denial, and to seek to deflect and shift the blame and responsibility," he told a meeting of Indian envoys in New Delhi.