In what is being reported as a major security lapse, Indian Prime Minister Narendra Modi's convoy was trapped on a flyover for 20 minutes by protesters in Punjab's Bhatinda.

The protesting farmers were demanding the resignation of a cabinet minister whose son has been accused over the deaths of farmers.

"This was a major lapse in the security of the PM," a statement from the federal home ministry said.

However, the Punjab chief minister said there had been no security lapse on the part of his government.

Modi, who arrived in Bhatinda on Wednesday, was supposed to fly to the National Martyrs' Memorial and later to the rally in a helicopter.

The trip was delayed by bad weather, and the delegation opted to go by road when visibility did not improve.

Mr Modi was also scheduled to address a rally in the city of Ferozepur, ahead of state elections. But the home ministry said the prime minister's convoy returned to the airport due to the security lapse.

The protesters were demanding the resignation of junior home minister Ajay Mishra, whose son has been accused in an incident that left eight people dead in October.

A car linked to Mr Mishra had ploughed into protesting farmers in Uttar Pradesh state, killing four men. Farmers alleged that the son, Ashish Mishra, was behind the attack, but the Mishras deny the allegation.