Indian police said on Monday they had killed three Sikh separatists fighting for a separate homeland known as “Khalistan”, the struggle for which sparked deadly violence in the 1980s and 1990s. The campaign for Khalistan was at the heart of a diplomatic firestorm last year after Indian intelligence operatives were linked to the killing of a vocal Sikh leader in Canada and an attempted assassination in the United States – claims New Delhi rejected. In the latest incident, the Khalistani rebels were killed after a gun battle in Pilibhit district in the northern state of Uttar Pradesh. The men were wanted for their alleged involvement in a grenade attack on a police outpost in Punjab state this month. Pilibhit police superintendent Avinash Pandey said officers had surrounded the men after a tip-off, with the suspects launching “heavy fire”. “In the retaliatory action, all three were critically injured and later died in hospital,” he said. Police recovered two assault rifles, two pistols and a large cache of ammunition. The three men belonged to Khalistan Zindabad Force, a separatist group, Punjab police chief Gaurav Yadav said in a statement. The Khalistan campaign dates back to India’s 1947 independence and has been blamed for the assassination of a prime minister and the bombing of a passenger jet.