Lakhimpur Kheri Senior Superintendent of Police, Poonam, said the search operation was carried on throughout the night.
Gandhi addressed two rallies in Assam on Wednesday in support of Kaliabor MP Gaurav Gogoi and Congress candidate from Lakhimpur constituency Anil Buragohain.
Verma was returning to his residence in Rajgarh area from office when he was shot on his leg.
A Muslim group from Lakhimpur Kheri district in Uttar Pradesh has launched a protest against the name of the man-eating tiger Mustafa, now lodged in the Lucknow Zoo
Police team recovered recently-manufactured seven country-made pistols and some semi-finished fire weapons.