Twenty seven people have been arrested in connection with online child sexual exploitation in Bradford.
The boys and men, aged 16 to 57, were questioned after being arrested at addresses across the city.
More than 60 devices were seized and safeguarding measures put in place for 26 children, police said.
Warrants were executed after claims that people had been contacting children online and were in possession of indecent images of children.
The 27 people were questioned and released under investigation or bailed while further inquiries take place, West Yorkshire Police said.
Police said parents and carers must monitor their children’s devices and report concerns during the coronavirus lockdown.
Det Ch Insp Alan Weekes said: “We urge parents and carers, particularly in the current climate where children are spending more time at home, to regularly monitor their children’s devices and report any concerns to the police or partner agencies, so these can be investigated fully.”
He said anyone attempting to contact children online “cannot hide behind their mobile phone or internet use”.
Adrian Farley, executive member for children and families at Bradford Council, said: “It’s a good result that the police have made these arrests.
“It sends out a strong message to anyone thinking of committing these sorts of crimes that grooming children online will not be tolerated, particularly at this time when children are spending more time online because of the coronavirus lockdown.
“It also shows that when partners and the public let the police know of potential offences, action can and will be taken.”
Earlier this month, international law enforcement agency Europol Europol warned that online child abusers are seeking to take advantage of the coronavirus pandemic.