Sections of Muslim groups in Sambhal protested against this, claiming that they had not received prior notice. They have too questioned the urgency, external with which the court ordered the exercise.
A second survey of the mosque was conducted on Sunday morning, which turned violent after a large group of protesters gathered outside the mosque and started shouting slogans at the survey team, police said.
Senior police official Aunjaneya Kumar Singh told The Hindu that the protesters allegedly pelted stones at the police, leaving them with no option but to use force to escort the group of observers to safety.
He added that tear gas shells and plastic bullets were fired to disperse the crowd.
Mr Singh identified the three victims as Naeem, Bilal and Nauman and said they died of bullet wounds sustained during the clashes.
Opposition leaders have criticized the state government and accused it of orchestrating the violence for political gain – a charge they deny.
“No one is allowed to take the law into their own hands,” Uttar Pradesh Deputy Chief Minister Brajesh Pathak told the Indian Express, adding that authorities were investigating the incident.
Mahmood Madani, president of Jamiat Ulama-i-Hind – a leading organization of Islamic scholars – condemned the controversy surrounding mosques in the country, saying they violated Indian laws.