Lone children as young as 14 have been detained at the Manston asylum seeker processing centre in Kent, a freedom of information request has revealed. According to the immigration rules, children should not be detained in short-term holding facilities such as Manston, apart from in exceptional circumstances, and holding them for more than 24 hours is unlawful. The Home Office revealed for the first time that between April and September 2022 it placed 17 children at Manston who they determined were between 14 and 17 years old. The freedom of information response showed that one child was 14; three were 15; six were 16; and seven were 17. The Guardian is aware of at least 10 children who were held for more than 24 hoursat the site, and who have embarked on legal actions against the government for unlawful detention. The tented site has generated headlines because of outbreaks of diphtheria and gastroenteritis, reports of assaults and drug use by guards, and other cases of unlawful detention. Home Office officials said they were not releasing data for the remainder of 2022 – the Manston site’s busiest months – as it would be publishing this at a later date. Enver Solomon, the chief executive of the Refugee Council, said: “Manston is not a suitable place to hold an unaccompanied child. We know from our work that they are highly traumatised and vulnerable, having already experienced unimaginable horror and upheaval. They need to be looked after in dedicated child welfare settings by skilled staff who care for them and keep them safe.” Benny Hunter, a campaigner for the rights of young asylum seekers, said: “It is shocking and appalling that children as young as 14 have been held in a detention camp at Manston, knowingly put in harm’s way, with their welfare concerns ignored. This kind of treatment will undoubtedly be damaging to children who we rightly recognise as vulnerable and whose best interests are supposedly enshrined in law.” A Home Office spokesperson said: “The Home Office does not routinely take unaccompanied children who have arrived by small boat to the national processing centre at Manston. “The usual process is to identify those individuals immediately on arrival and direct them to appropriate care. In exceptional circumstances, it may be necessary to take unaccompanied children to Manston.”