The violence had occurred as a meeting was being held in Naglabadhod in defiance of prohibitory orders to demand withdrawal of cases registered in connection with August 27 violence in Kawal.
Authorities are trying to identify the people who had provoked the violence during the meeting, an official said.
Police said 40 people have been booked at Sekeda police station in connection with the killing of the photographer and holding of the meeting.
The UP Home Secretary said that permission was not given for the meeting yesterday but could not reply as to how thousands of people were allowed to gather at the village.
He said senior officers including ADG, Law and order Arun Kumar and four IGs are camping in the district.
Police said a video of a violent incident which became viral on internet had added to the tension and the UP government today said that the footage was not even of the country.
Asking people not to pay heed to rumours, IG, Crime Ashish Gupta told reporters in Lucknow that some unscrupulous elements were using social networking sites and SMSes to spread rumours to create tension.
"A video is also being circulated through Facebook and other networking sites to create tension. I want to tell you that the said video is probably over two years old and is of some other country. I appeal to people that they should not pay heed to it", Gupta said.
