India directly accused Pakistan of being behind Sunday’s separatist attack on an army base near their disputed frontier that killed 17 soldiers, in one of the most deadly attacks in Kashmir in a quarter-century-old insurgency.Four ‘fidayeen’ - or commando-style gunmen willing to fight to the death - were confirmed killed after penetrating the base in Uri near the Line of Control with Pakistan, an Indian army spokesman said.Prime Minister Narendra Modi strongly condemned what he called the ‘cowardly terror attack’.‘I assure the nation that those behind this despicable attack will not go unpunished,’ Modi said in a series of Twitter posts.There has been no claim of responsibility.The raid comes amid heightened tension in India’s only Muslim-majority region, which has faced more than two months of protests following the July 8 killing of a popular separatist commander whose Hizbul Mujahideen group is based in Pakistan.At least 78 civilians have been killed and thousands injured in street clashes with Indian security forces, who have been criticized by human rights groups for using excessive force.In an even stronger response, Indian Home Minister Rajnath Singh tweeted: ‘Pakistan is a terrorist state and should be identified and isolated as such.’Pakistan rejected allegations that it was involved. ‘India immediately puts blame on Pakistan without doing any investigation. We reject this,’ foreign ministry spokesman Nafees Zakaria told Reuters.India and Pakistan have fought two of their three wars since independence over Kashmir. Both claim the former princely state of Jammu and Kashmir in full but rule it only in part.