Two men arrested on suspicion of sexual assault and false imprisonment at an Islamic girls' school have been released on bail.
A third man arrested on suspicion of false imprisonment at the school in Lancaster has been released without charge.
Searches were continuing within the grounds of the Jamea Al Kauthar school as police investigated claims of sexual assault and false imprisonment.
Police were informed at the weekend of an alleged incident involving "a small number of teenage girls" at the school last Tuesday. The report made on Saturday was said to have raised concerns over the welfare of the girls.
Detectives executed a search warrant of the premises last night and also arrested three men at the site.
A 40-year-old man from Bolton and a 30-year-old man from Blackburn were interviewed and had now been bailed pending further inquiries, a police spokeswoman said. A 53-year-old man from Blackburn was questioned on suspicion of false imprisonment and was released without charge.
Police would not comment on whether they were members of the teaching staff but it is understood they are linked to the school.
Bosses at Jamea Al Kauthar said they were co-operating with what police labelled a "complex investigation" and added it anticipated the matter would be "cleared up soon".
Superintendent Andy Webster said officers were currently focused on the one alleged incident and they were trying to ascertain whether the report related to existing or former pupils of the school.
He said: "We are still at the very early stages of what is a complex investigation and we have dedicated officers working to establish the full facts. Our aim at this stage is to respond to the information given to us in a proportionate and sensitive way. We will seek to minimise the impact and the disruption to the school and our local communities while we investigate the allegation."