A man carrying a country-made pistol was arrested shortly before an election rally by Congress president Sonia Gandhi in Almora on Sunday, prompting police in Uttarakhand to sound a red alert in the state.

Kedar Singh was arrested while trying to sneak into the venue of the rally in the hilly township just before Sonia addressed the gathering at about noon, Almora's Superintendent of Police Satish Kumar Shukla told PTI.

A red alert was sounded across Uttarakhand, particularly in Haldwani and Dehra Dun where Sonia is to address rallies during the last leg of her campaign to drum up support for the state's ruling Congress ahead of Assembly polls later this month.

Shukla said Singh was being interrogated. Initial reports said Singh had identified himself as a resident of nearby Bageshwar district. "We are verifying reports regarding his identity," Shukla said.

Security around the venues for other rallies to be addressed by Sonia was tightened, with dog squads and anti-terrorist squads being deployed there.

Sources said no changes had been made in Sonia's itinerary following the incident.