Four deaths were reported from Meerut district, while the boy was killed in a stampede in Varanasi when a violent mob was being chased by police personnel on Friday, they said.
After Friday prayers, six people were killed as protesters clashed with the police at several places in the state. They hurled stones and torched vehicles, the officials said.
There have been reports of firing on police personnel deployed to maintain law and order, they said.
Director General of Police O P Singh on Friday said that 50 policemen were seriously injured in the violence.
Violence during the anti-Citizenship (Amendment) Act protests has so far claimed lives in Bijnor, Sambhal, Firozabad, Kanpur, Varanasi and Meerut in the state.
Clashes with police were also reported from Bhadohi, Bahraich, Amroha, Farurukhabad, Ghaziabad, Varanasi, Muzaffarnagar, Saharanpur, Hapur, Hathras, Bulandshahr, Hamirpur and Mahoba districts.
At many places, police used lathis, lobbed teargas shells and, according to some officials, rubber bullets when they failed to contain angry mobs.
Internet services have been suspended across major cities in Uttar Pradesh, following the state government orders.