The labourers were on their way to Bahraich from Lucknow to caste their vote in the panchayat election taking place today when they met with the accident on Lucknow-Bahraich highway, police said.
The incident happened after the labourers got buried under the dumper after it overturned, police said, adding that by the time locals and police could pull them out, seven men had already died.
So far, only four of the deceased have been identified -- Mayaram Lodh (35), Nanku (23), Om Prakash (25) and Ram Naresh (36).