Officials also said the fact that these incidents, including an earlier one, where repoll was held at some booths after the second phase of election in Rampur Lok Sabha constituency, the stronghold of another SP minister Azam Khan, "has put the SP in bad light".
Opposition parties has accused the ruling SP of indulging in such illegal means.
"What else justifies the fact that all such incidents have taken place in the areas touted to be pocket boroughs of the SP and the Yadav clan," questioned Vijay Bahadur Pathak, state spokesman of the Bharatiya Janata Party.
Uttar Pradesh former chief minister and Bahujan Samaj Party chief Mayawati has twice in the past has aired her apprehension that the SP chief could rig the polls.
"I am informed that the SP knows its fate in the general election and can resort to anything...I therefore urge the EC to take note of the situation and ensure deployment of more paramilitary forces in the remaining phases of polls in the state," she said.
