Fifteen men have been arrested and questioned as part of an investigation into allegations of historic child sexual exploitation in Rotherham.
The alleged offences, including rape, are said to have taken place between 2003 and 2009 against four girls.
The arrests, which relate to three separate investigations, were made as part of the National Crime Agency's (NCA) Operation Stovewood.
All 15 men have been released while investigations continue.
The NCA said nine men, aged between 36 and 49, were arrested on suspicion of raping a girl between 2003 and 2008.
The arrests took place in Rotherham, Sheffield, Doncaster, Blackburn, Wakefield and County Durham.
Five more men from the Rotherham area, aged between 29 and 62, were arrested in connection with the alleged abuse of two girls between 2007 and 2009.
A 51-year-old man was also arrested in Conisbrough by NCA officers on suspicion of sexually abusing a 14 or 15-year-old girl in 2008.
South Yorkshire Police asked the NCA to lead an independent investigation in 2015, following a report by Prof Alexis Jay in 2014 which found abuse in Rotherham had been ignored by agencies.
Stovewood is the largest law enforcement investigation into non-familial child sexual abuse in the UK.
NCA regional head of investigations Rob Burgess said: "This latest operational activity means we have now questioned more than 190 people as part of Operation Stovewood."