Terming Pakistan-based terror groups like Lashkar-e-Taiba and Jaish-e-Mohammad a constant security threat, Director of Intelligence Bureau Asif Ibrahim today said return of the battle-hardened youth from Iraq and Syria poses a new challenge to the country.

"Pakistan-based Lashkar-e-Taiba and Jaish-e-Mohammad remain a constant threat to our national security," he said addressing the 49th annual conference of DGPs, IGPs of all States, Union Territories and Central Police Organisations heads here organised by the Intelligence Bureau.