At a polling station some BJP workers raised the “har har Modi” slogan when he left the venue.
Amethi is one of the most keenly watched constituencies in this phase. The BJP’s Smirti Irani and AAP’s Kumar Vishwas have mounted a spirited challenge.
Amid brisk voting, the turnout reached 27.80% at 11am.
Earlier in the day, Vishwas accused Congress workers of indulging in booth capturing to save the prestigious seat, won by Rahul in 2004 and 2009.
"Booth capturing is going on at booth number 42 of Mehmoodpur...," Vishwas alleged on Twitter.
In another tweet, he alleged that information about booth capturing, fake voting and intimidation of workers was coming from various places, but the observers and district administration were not taking any action on complaints being sent through phone, email and SMSes.
District magistrate Jagat Raj Tripathi, however, dismissed the charges. "No such complaint has been found correct. Polling is going on smoothly," he said.
(With inputs from PTI)