Shimla/Dehra, May 31 -- Security agencies have heightened surveillance in Himachal Pradesh after two back-to-back incidents raised national security concerns - one involving a US citizen who was found roaming near a high-security Army zone in Shimla, and another involving a local youth arrested in Kangra for possessing objectionable content on his phone.

On May 28, a man identified as Prateek Stylom, a US passport holder of Indian origin and resident of Sector-45, Noida, was seen moving suspiciously near the Army Headquarters Track Command (ARTEAC) in Shimla.

According to Army Intelligence sources, Stylom was seen asking Army personnel specific and sensitive questions such as the identity of the Army commander and the number of officers ...