Police are questioning 10 men suspected of child trafficking following a series of raids in Manchester and the north-west connected to a major inquiry into the sexual exploitation of young girls.

The arrests followed allegations that the men befriended vulnerable girls in Manchester city centre and plied them with food, alcohol and drugs before carrying out abuse at sex parties.

Around 100 detectives have been involved for three months in Operation Windermere, one of the largest child sexual exploitation investigations ever carried out by the serious crime division of Greater Manchester police (GMP).

Police said up to 39 young girls, some as young as 14, were helping with the inquiry, which was focusing on a "core group" of four to six alleged victims.

It is believed the arrested men met girls outside shops and at bus and train stations in Manchester city centre, and offered them food and takeaways. The grooming would then progress to giving them drink and drugs before they were allegedly taken to parties in Manchester and Salford and encouraged to engage in sexual activity with older men.

The identities of the arrested men were not disclosed, but police said they were aged between 18 and 28. Most were held in raids this morning on properties in Manchester and Salford, while one man was arrested in Buxton, Derbyshire.

All 10 men were arrested on suspicion of trafficking within the UK for the purposes of sexual exploitation, but further charges were being considered.

Around half the girls were in local authority care and all were classed as vulnerable, with many from broken homes and many living on the periphery of society.

GMP Assistant Chief Constable Terry Sweeney said the operation was part of a series of investigations into child sexual exploitation currently under way. Arrests were made in Bury and Rochdale in recent weeks.

He also appealed for the public's help in combating sex gangs that prey on vulnerable youngsters. He said the girls had been the victims of "classic grooming".

"I think the abuse can be stopped by the community working with us and telling us what is going on," he said.

"But more importantly, from our point of view, [it can be stopped by] reaching out to those victims to get them to come on board with us and work through the criminal justice process, because if we don't do that together the offenders remain out of reach of the law, and that's the last thing any of us want.

"We need the public to come forward to help us protect these young people and prevent them becoming victims of this horrific abuse.

"If you see young males talking girls into flats and houses, the girls can be very, very young and the males in their 20s, why are they there? We would like the public to tell us about it."

There were "a number" of similar operations going on in the area, Sweeney said. "I cannot go into details as that could jeopardise the operations, but people need to know this issue is at the top of GMP's priorities," he said. "We work closely with local authorities, and other organisations such as Barnardo's, to address the specific issue of adults befriending and grooming younger people for sex."