Timer devices could have been used to detonate three low-intensity bombs on Tuesday evening in a crowded shopping area of this temple town, a senior police official said on Wednesday.
A Special Task Force team from Lucknow has also rushed to this town for further investigation.
Senior Superintendent of Police RK Rai said timer devices could have been used to set off the three blasts.
The bombs kept in tiffin boxes and tied to cycles went off at five minutes interval after 7 pm near Baldev Plaza, Ganesh crossing and and Jalkal building in the busy Golghar area, he said.
Security has been beefed up in sensitive areas of the city which recently witnessed communal violence . All exit points from the city has been sealed.
Security around the famous Gorakhnath temple, which has been on the hit list of terrorists, has also been tightened.
Police are also investigating whether the blasts have any link with the recovery of ten kilograms of explosives and 20 litres of ammonium nitrate from Faizabad railway station in the wee hours of Wednesday.
Meanwhile, five persons, who were injured in the blasts, are now out of danger and being treated at the district hospital in Gorakhpur.
The injured have been identified as Rajesh Kumar (32), Santosh Singh (35), Sanjay Rai (35), Ganesh (41) and Rameshwar Patel (30).