Five had come on two bikes to attack Pardeep Singh, the police said.
A Dera Sacha Sauda follower, who was an accused in a 2015 sacrilege incident, was shot dead on Thursday by five unidentified assailants in Punjab's Faridkot district, police said.
Pardeep Singh was opening his dairy shop in Kotkapura when he was shot dead and the incident was caught on a CCTV camera installed nearby, they said, adding his gunman also sustained bullet injuries.
Singh was one of the accused in a case of theft of a 'bir' (copy) of the Guru Granth Sahib in 2015 in Faridkot and was currently on bail.
Chief Minister Bhagwant Mann appealed for peace, and said no one will be allowed to disturb peace in the state.
"Punjab is a peace loving state where mutual brotherhood of people is very strong...No one will be allowed to disturb the peace of Punjab...Strict instructions to the civil and police officials to maintain the peace and tranquillity in the state," said Mann in a tweet.
Speaking to reporters, Inspector General of Police (Faridkot Range) Pradeep Kumar Yadav said police have got some leads and are working on them.
He said the assailants will be arrested soon.
Police were also examining the CCTV footage of the incident which showed that the five had come on two bikes.
The sacrilege incidents in Faridkot in 2015 had triggered protests in the district.Two persons were killed in Behbal Kalan while some people were injured at Kotkapura in Faridkot after police fired at protesters in October 2015.
Dera Sacha Sauda chief Gurmeet Ram Rahim Singh is serving a 20-year jail term for raping two women disciples at his ashram in Sirsa, where the dera is headquartered. He was convicted by a special CBI court in Panchkula in August 2017.