Islamabad: With India casting suspicion on Pakistani militant groups in the Mumbai terror attacks, analysts and diplomats warned on Friday that slowly warming relations between the nuclear-armed rivals could suffer a reversal, with potentially serious repercussions for the entire region.

Pakistani authorities have denied vehemently any involvement in the three-day rampage by groups of gunmen in India's commercial capital which left at least 195 people dead. But in contrast with bellicose rhetoric in previous times of crisis with its neighbour, Pakistan coupled its denials with conciliatory gestures.

In the past, Pakistan's intelligence apparatus itself was accused of helping Pakistan-based militant groups carry out attacks on Indian soil - most notoriously in 2001, when the militant organisation Jaish-e-Mohammad attacked India's Parliament.

Even in the first hours of the Mumbai crisis, India used veiled although widely understood language to suggest Pakistani involvement. But as investigators began interrogating captured assailants, reportedly finding Pakistani nationals among them, the accusations turned sharper.

"Preliminary evidence ... indicates elements with links to Pakistan are involved," India's foreign minister Pranab Mukherjee said.