Posters of the Islamic State (IS) surfaced near an army cantonment in Himachal Pradesh's Solan district on Tuesday, a police official said.
The posters and a flag saying "ISIS Coming Soon", written in English, Hindi and Urdu, surfaced on the walls near Subathu cantonment, the official told IANS.
Subathu is some 50 km from the state capital, Shimla.
One of the posters warned of triggering three bomb blasts from Subathu to Nepal.
The police said investigations were on and also asked the locals not to feel threatened by the posters.
Earlier, a temple in Solan was defaced with "ISIS coming soon" written over its walls in English and Arabic.
The incident happened in January in Dharampur.
In December 2016, a 23-year-old man from Bengaluru with alleged IS links was arrested by a National Investigation Agency (NIA) team and the local police from Banjar area in Kullu district.
The suspect Abeed Khan was arrested from a church where he was staying with a fake identity for several months, the police said.