Three people were killed and scores of others, including around 20 security personnel, were injured as protesters opposing a court-ordered survey of a Mughal-era mosque here clashed with police on Sunday.

The protesters torched vehicles and pelted stones at the police, who used tear gas and batons to disperse the mob. "Shots were fired by the miscreants... the PRO of the superintendent of police suffered a gunshot to the leg, the police circle officer was hit by pellets and 15 to 20 security personnel were injured in the violence," Moradabad Divisional Commissioner Aunjaneya Kumar Singh said.

He said that a constable also suffered a serious head injury, while the deputy collector fractured his leg.

Internet services have been suspended in Sambhal tehsil for 24 hours and the district administration declared a holiday on November 25 for all students up to Class 12.

Purported images shared on social media showed protesters pelting stones at cops from atop buildings and in front of the Shahi Jama Masjid. Later, police personnel were purportedly seen cornering and hitting people as they tried to disperse a large crowd in a narrow alleyway.

Visuals on social media showed a lane strewn with a large number of slippers, bricks and stones. In another purported clip, some police personnel in riot gear were seen firing gunshots towards a lane while flames leapt and smoke billowed into the air in the background.

One purported clip showed Superintendent of Police (SP) Krishan Kumar urging stone-pelters not to indulge in violence. "Do not spoil your future for these politicians," he is heard saying through his megaphone.

Tension has been brewing in Sambhal since Tuesday when the Jama Masjid was surveyed on the orders of a local court following a petition that claimed that a Harihar temple stood at the site.

"Three people, identified as Naeem, Bilal and Nauman, have been killed," Singh said, adding that preparations were underway for their post-mortem examination.

Fifteen people, including two women, have been detained and a probe has been launched, the official said.

He added that those accused in the violence would be booked under the stringent National Security Act (NSA).

The trouble started on Sunday morning when a large group of people gathered near the Shahi Jama Masjid and started shouting slogans as the survey team began their work.

District officials said the survey could not be completed on Tuesday and was planned for Sunday morning to avoid interference with prayers that are usually held in the afternoon.

SP Kumar told reporters that there was peace in the area at the moment.

"A request has been made to the district magistrate to suspend mobile internet services for 24 hours in Sambhal which has been approved by the government. Internet service will remain closed for one day in Sambhal tehsil," he said.

The SP added that an FIR has been registered at the Sambhal police station and the 20-22 policemen, who were injured, are giving their statements.

"Their medical examination is also being done and a case will be registered," he said, adding that the constable who suffered an injury to the head has been sent to the Meerut Medical College and his condition is critical.

Kumar said the mobile phones of those who have been detained were being checked.

Elaborating on the incident, Singh said when the survey was leaving after the survey, some people started pelting stones.

"There were groups on three sides. One from the front, one from the right and one from the left. They were continuously pelting stones. Police used force so that the survey team could be taken out and escorted safely. Tear gas shells were also fired. Plastic bullets were used," the divisional commissioner said.

"So far, 15 people have been detained... This is definitely an act of provocation in which lives have also been lost," he added.

Singh said the survey work was being done under court orders. "It was going on peacefully... Nothing has been done in the survey that may tamper with the structure of the mosque. In fact, in the stone-pelting that happened today, stones were definitely thrown at the mosque," he added.

"We are talking to the public representative. So far, the situation is under control, and completely peaceful. Force has been called from outside to keep the situation under control," he said.

Singh said that efforts are on to identify the people who had provoked the crowd.

Samajwadi Party chief Akhilesh Yadav lashed out at the BJP, saying its government and the administration orchestrated the violence "to divert attention from electoral malpractice". "A survey team was deliberately sent in the morning to disrupt discussions about the election. The intention was to create chaos so that no debate on election issues could happen," he said at a press conference in Lucknow.

The BJP hit back, alleging that the INDIA alliance has been trying to create unrest since the Lok Sabha polls, and said that those who do not agree with judicial orders should take legal recourse.

"Nobody has any right to break the law. If a court has passed an order, it will be implemented. The judicial process is available for those who want the order amended," party spokesperson Nalin Kohli said.

According to the local administration, a second survey by an "Advocate Commissioner" as part of a court-ordered examination into the disputed site started around 7 am and a crowd began gathering there.

Director General of Police Prashant Kumar said police and civil administration officials are on the ground and strict action will be taken against the culprits.

Additional police units have been deployed near the mosque to ensure law and order and officials are closely monitoring the situation.

On Saturday, the Sambhal district administration "bound down" 34 people on a bond of up to Rs 10 lakh on apprehension of a breach of peace.

Among them was Mamlukur Rahman Barq, the father of the Samajwadi Party's Sambhal MP Zia ur Rahman Barq, Subdivisional Magistrate Vandana Mishra told PTI.

Supreme Court lawyer Vishnu Shankar Jain, who is a petitioner in the case, had said the Court of Civil Judge (Senior Division) ordered the constitution of an "Advocate Commission" to survey the mosque.

The court has said that a report should be filed after conducting a videography and photography survey through the commission, he had said.

The Central and Uttar Pradesh governments, the mosque committee and the district magistrate of Sambhal have been made parties in the petition concerning the mosque, Jain said last Tuesday.

Vishnu Shankar Jain and his father Hari Shankar Jain have represented the Hindu side in many cases related to places of worship, including the Gyanvapi Mosque-Kashi Vishwanath temple dispute.

Gopal Sharma, a local lawyer for the Hindu side, claimed that the temple that once stood at the site was demolished by Mughal Emperor Babur in 1529.