A day after a powerful explosion jolted Himachal Pradesh’s Nalagarh town, security agencies on Friday intensified investigations amid a chilling social media claim by Khalistani-linked outfits, even as police stopped short of confirming the authenticity of the threat.

Police said multiple teams have been formed to scan CCTV footage and reconstruct the sequence of events after the blast that occurred early Thursday near the Nalagarh police station in Solan district. Forensic experts from the state’s Forensic Science Laboratory have collected samples from the site to determine the nature of the explosive used.

The probe took a more serious turn after a social media post surfaced, claiming to be issued by the banned outfit Babbar Khalsa International (BKI) along with a lesser-known group, the Punjab Sovereignty Alliance (PSA).

The post alleged that an improvised explosive device (IED) was used in the blast and described it as “retaliation” for the Himachal Pradesh Police’s alleged failure to act against the smuggling of synthetic drugs from Himachal into Punjab.

More alarmingly, the post carried an explicit warning, claiming that if action was not taken, IEDs would be planted in vehicles and police headquarters — a threat that has raised red flags across security establishments.

Police officials, however, have not commented on the content or credibility of the post so far. Instead, in an official statement issued on Friday evening, authorities said investigative efforts were focused on physical evidence and technical inputs.

Police also confirmed coordination with the National Investigation Agency (NIA) and the Punjab Police to examine possible inter-state and transnational links.

Residents of Nalagarh said they were shaken awake by the explosion on New Year’s morning. The impact was so intense that windows of nearby buildings — including those of an Army canteen located about 40 metres from the blast site — were cracked. Locals said the sound of the explosion could be heard from a distance of 400 to 500 metres, amplifying fears of a targeted attack near a sensitive police installation.

A case has been registered at the Nalagarh police station under Sections 324(4) (mischief) and 125 (act done so rashly or negligently as to endanger human life) of the Bharatiya Nyaya Sanhita, along with provisions of the Explosive Substances Act.

Security agencies are also viewing the incident in the wider context of similar attacks in neighbouring Punjab, where police stations have previously been targeted.

Punjab’s Director General of Police has repeatedly alleged that Pakistan-backed networks are attempting to disturb peace, with masterminds operating from North America, Europe, Southeast Asia and Gulf countries — a pattern investigators are now examining closely in the Himachal blast case.