Harminder Singh Mintoo, the chief of Khalistani Liberation Force, died of cardiac arrest in Nabha Central Jail in Patiala on Monday, the police said. Mintoo, 50, was taken to a hospital after he suffered a heart attack. He was declared brought dead, Punjab Police Inspector General AS Rai told PTI.

Mintoo was facing several charges, including terror charges, and was arrested from the Delhi airport in 2014.

In November 2016, Mintoo, along with five other inmates, had escaped Nabha jail after a group of armed men in police uniform stormed the prison. They were nabbed from Nizamuddin Railway Station a day later.