Sambhal (UP) | Three people were killed and scores of others, including around 20 security personnel and four personnel of the administration, 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.

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 also 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.

Kumar also told reporters that videos are going viral at many places that the police have opened fire.

Refuting such allegations, he said, "Police have used pellet guns. No weapons were used that could take anyone's life. As many as 21 people have been detained. Several kinds of weapons have been recovered from them. At the spot where the firing took place, many shells of different bores have been recovered."

"Weapons have also been recovered from the houses of the detained people. Firing took place from a house in Nakhasa police station area, from where two women have been detained," he added.

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.

Twenty one people, including two women, have been detained and a probe has been launched, the official said, adding that those accused in the violence would be booked under the stringent National Security Act (NSA).

"The casualty count stands at three. The reason for the death of two of them is clear -- bullet wounds from countrymade pistols. The reason for the death of the third person is not clear, but it will be after the post-mortem examination," said District Magistrate Rajender Pensiya.

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.

The 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.

Kumar told reporters later that there was peace in the area.

"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, were giving their statements.

He said that the constable, who suffered an injury to the head, has been sent to the Meerut Medical College and his condition is critical.

Elaborating on the incident, the divisional commissioner said when the survey team was leaving after completing the exercise, 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," Singh said.

"This is definitely an act of provocation in which lives have also been lost," he said and appealed to people to maintain peace.

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 said.

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

Supreme Court lawyer Vishnu Shankar Jain, who is a petitioner in the case, earlier 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 said.

On Sunday, Jain urged the Archaeological Survey of India (ASI) to take control of the "temple".

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.