Foreign Secretary Nirupama Rao has warned of a clear and present danger to the international community from militants in Pakistan after a bomb attack on the Indian embassy in Kabul that it has hinted may have come from across the border.
Thursday's blast, for which the Taliban claimed responsibility, killed 17 people but harmed no embassy staff.
"The international community and indeed the people of Afghanistan face a clear and present danger from the perpetrators of such wanton acts of terrorism and their patrons residing across the border," Rao said.
"The attack was clearly the handiwork of those who are desperate to undermine Indo-Afghan friendship," Rao said in a statement late on Saturday.
Rao had gone to Kabul on Friday to inspect the site of the bomb attack but had declined to assign blame at the time, when asked if India thought Pakistan was behind the attack.
India has in the past accused Paskistan's ISI spy agency of being behind attacks on Indian interests in Afghanistan. An attack on the same Kabul embassy last year killed 58 people.
After a tour of the attack site, Rao met Afghan President Hamid Karzai, Foreign Minister Rangeen Dafdar Spanta and National Security Adviser Zalmai Rassoul.
"They were unanimous in their view that the attack was carried out by elements from outside Afghanistan seeking to damage the excellent relations that exist between India and Afghanistan," the statement said.
Analysts say militants may be trying to force India to scale down its presence in Afghanistan, where it is spending $1.2 billion dollars on development projects, and pre-empt any plans by the West to involve India in stabilising the region.
Pakistan competes with India for strategic space in Afghanistan and sees it as a fall-back position in the event of a war with India.
India-Pakistan rivalry has been highlighted as a factor that could complicate efforts to stabilise the region.
Pakistan condemned the Kabul blast and rejected insinuations it was involved.
"Regrettably, the Indian officials and media continue to make baseless insinuations," the Pakistani Foreign Ministry said in a statement issued on Saturday.
"These have become impulsive reactions betraying a strange mindset," the ministry said.
The ministry said Pakistan had recently suggested a meeting of a joint panel on terrorism, set up as part of a broad peace process launched in 2004 but which India put on hold after a militant assault on Mumbai last November.
"Instead of recrimination India should opt for cooperation," the Pakistani ministry said.