Six people were killed as anti-citizenship law protesters clashed with police after Friday prayers at several places in Uttar Pradesh, hurling stones and torching vehicles, officials said.
Director General of Police O P Singh, however, confirmed only five deaths during the violence in about 20 districts.
Singh told PTI that two people lost their lives in Bijnor and one each in Meerut, Sambhal and Firozabad. But officials reported a death in Kanpur as well.
The cause of death would be known after a post-mortem on the victims, officials said. Singh maintained that none of the deaths were due to police firing.
Several people were injured. The DGP said 50 policemen were seriously hurt.
The violence comes a day after police dealt with angry protesters in Lucknow and Sambhal districts -- and amid internet curbs in many districts to curb rumour-mongering.
Stone-pelting or more serious clashes with police were also reported from Bhadohi, Bahraich, Amroha, Farrukhabad, Ghaziabad, Varanasi, Muzaffarnagar, Saharanpur, Hapur, Hathras, Bulandshahr, Hamirpur and Mahoba districts.
At many places police used lathis, lobbed tear-gas shells and, according to some officials, rubber bullets when they failed to contain angry mobs.
Police were often targeted when they stopped people from taking out processions in defiance of prohibitory orders in places all over the state.
At least six vehicles, including those of police, were set ablaze in Firozabad, forcing police to use tear-gas shells to disperse the mobs.
Half a dozen vehicles, mostly of policemen, were also torched in Kanpur's Babu Purwa area and six people were hurt in the city, Additional DG (Kanpur zone) Prem Prakash said.
He said 10 people allegedly involved in arson and stone- pelting were arrested.
In Meerut's Islamabad locality, protesters targeted a police post, setting fire to some furniture and a motorcycle parked nearby.
Internet services were suspended across major cities in Uttar Pradesh, following state government orders.
These included Lucknow, Kanpur, Allahabad, Agra,Aligarh, Ghaziabad, Varanasi, Mathura, Meerut, Moradabad,Muzaffarnagar, Bareli, Firozabad, Pilibhit, Rampur, Saharanpur, Shamli, Sambhal, Amroha, Mau, Azamgarh and Sultanpur.
Lucknow and Aligarh, which have been the scenes of clashes in recent days over the citizenship law, remained largely calm.
In Aligarh, where a red alert had been sounded by the administration, Friday prayers passed off peacefully, SSP Akash Kulhari said.
Peace calls were made from mosques in Muslim-dominated areas in the morning, including by the Shahr Mufti Khalid Hamed who urged people to ignore rumours.
Security was tightened in the state capital with the deployment of armed police, and senior officials said the Friday prayers passed off peacefully in Lucknow.
But many people stayed away from major markets, a day after a man died during a protest demonstration in Lucknow's Old City.
In areas deemed sensitive by authorities, police conducted flag marches.
In Bahraich, six people, including two policemen, were injured. Around 40 men were arrested there.
In Bhadohi, people taking part in a protest march clashed with police. Officials said tear-gas shells were fired and mild force used against them.
Bhadohi SP Ram Badan Singh said the protesters hurled stones and damaged several two-wheelers.
Large demonstrations were organised after Friday prayers in Gorakhpur, the home district of Chief Minister Yogi Adityanath.
Police fired tear-gas shells in Gorakhpur's Khoonipur area to disperse protesters. There was tension in Ghantaghar, Shahmaroof, Nakhas and Ismailpur areas as people came out of mosques in large numbers and held demonstrations.
Clashes also took place in Chandausi area in Sambhal district, where two state roadways buses were damaged a day earlier. A case was registered against local Samajwadi Party MP Shafiqur Rehman Burq for defying prohibitory orders.
In Ghaziabad district, police reported stone-pelting at Muradnagar and Sahibabad's Pasonda by people stopped from taking out processions. In Pasonda, police arrested 30 people.
The amended law allows citizenship to Hindus, Christians, Sikhs, Buddhists and Parsis who entered India before 2015 after facing religious persecution in three neighbouring countries. The list excludes Muslims.