FOUR of the 13 men arrested in an investigation into a child sex ring were last night released on police bail.

Twelve men were arrested in a series of raids across Oxford at dawn yesterday. A 13th man was arrested at about 1pm.

The men were arrested on suspicion of a range of offences, including rape, causing prostitution of girls under 18, grooming, administering drugs with the intent to commit rape and sexual activity with a child.

Police have identified 24 girls - aged between 11 and 16 - they believe were linked to the child sex ring.

The arrested men are aged between 21 and 37.

Tonight police spokesman Alice Adderley said four of the men - aged 23, 31, 34, and 37 - had been released on police bail until April 19.

It had not been released last night which offences these men had been arrested on suspicion of to distinguish them from the nine still being held by detectives.

Thursday's raids were dubbed Operation Bullfinch and come after a lengthy investigation by Thames Valley Police and Oxfordshire County Council's social services team.

Police reused to say where the raids were made as they are worried it would put suspects or their families at risk of attacks.

A five-page report on today's raids is in Friday's Oxford Mail.