MUMBAI — The northern Indian city of Sambhal is on alert after four people died and dozens were injured in violent clashes over a centuries-old mosque on Sunday.

Clashes broke out between protesters and the police during a court-monitored survey of the Shahi Jama Masjid (mosque), a federally-protected 16th-century monument.

Authorities in Uttar Pradesh state, where Sambhal is located, have registered four cases in connection with the violence and have suspended internet services and shut schools in the area for a day.

The survey was ordered by a local court last week, hours after a petition claimed that the mosque had been built on the site of a destroyed temple.

Videos and images of the clashes shared on social media show slippers, bricks and stones strewn around the mosque.

Protesters allege that four men were shot in police firing but authorities have denied this.

"No weapons were used that could take anyone's life," Superintendent of Police Krishan Kumar told the Hindu newspaper.

The controversy around the Shahi Jama Masjid is the latest in a series of disputes around mosques in the country, where Hindu groups have claimed that Mughal rulers destroyed temples to build them.

Legal cases pertaining to these claims are currently being fought by Muslim groups in various courts.

In Sambhal, tensions have been brewing since Tuesday, after a local court ordered a video-recorded survey of the Jama Masjid. The survey was ordered hours after a petition claimed that the mosque was built after Mughal ruler Babur destroyed the Hari Har temple in the 1520s.

Authorities in Uttar Pradesh, which is governed by the Bharatiya Janata Party (BJP), conducted an initial survey of the mosque the same day.

Sections of Muslim groups in Sambhal protested against this, alleging that they were not given any prior notice about it. They have also questioned the urgency with which the court ordered the exercise.

A second survey of the mosque was held on Sunday morning, which turned violent after a large group of protesters gathered near the mosque and began shouting slogans at the survey team, police say.

Top police official Aunjaneya Kumar Singh told the Hindu that protesters allegedly pelted stones at the police, leaving them with no option but to use force to escort the survey team to safety.

He added that tear gas shells and plastic bullets were fired to disperse the crowds.

Opposition leaders have criticised the state government and accused it of orchestrating the violence for political gain - a charge it denies.

"No one is allowed to take law into their own hands," Uttar Pradesh's Deputy Chief Minister Brajesh Pathak told the Indian Express newspaper, adding that authorities were investigating the incident.

Mahmood Madani, president of Jamiat Ulama-i-Hind, a leading organisation of Islamic scholars, condemned disputes around mosques in the country, saying they violate Indian laws. — BBC