British officials at the embassy in Tel Aviv and consulate in Jerusalem have been reporting their concern about Israel’s treatment of Palestinians to their superiors in London, according to newly released documents.

In previously classified memos, diplomats told bosses at the Foreign and Commonwealth Office about Israel’s “worrying” trend of using a controversial measure to detain Palestinian youngsters in jail without charge or trial.

They also cite several cases of “unjustified” lethal action against Palestinian by Israeli security forces, saying this raises “concern over extrajudicial execution”.

In a series of messages sent from the British compounds, released under a Freedom of Information request, envoys detail case studies of Palestinians killed, including one man “shot in the back as he was running away”.

They also list the number of Palestinian minors held without access to lawyers or even parents in what is known as administrative detention, with hundreds of children as young as 14 held in Israeli military prisons in the West Bank and East Jerusalem. They note that there are two Palestinian prisoners aged 13 or younger.

In one of the most recent diplomatic cables, sent earlier this year, British officials say there is now “widespread use of administrative detention” with 800 Palestinians held under this measure, “the highest since 2008”. They say this includes 15 children.

A Consulate official, in a redacted message sent in May of this year, also notes that “Israeli authorities have demolished 235 [Palestinian] structures, displacing 429 people including 242 children”.

In an email sent to former Middle East Minister Tobias Ellwood late last year, officials quote non-governmental organisations reporting that 8,000 Palestinian children have been prosecuted under Israeli Military Law in the last 16 years, concluding that “the number of children affected remains a concern, as is their treatment in custody”.

In another, an embassy official in Tel Aviv chides the “lack of compliance to Israeli procedure prohibiting blindfolding and the tying of children’s hands behind their back”.

Despite Israel’s own military regulations forbidding them, the Embassy says UNICEF reported that “87 percent of children arrested in 2015 have reported the use of painful restraints,” while a similar number say they were blindfolded.

They say that, of the 40 recommendations made in a 2012 report, Israel “has only implemented one – the separation of children from adults whilst in custody”.

Of particular concern to the British officials appears to have been the number of Palestinian minors detained in East Jerusalem, saying this had “exploded from previous years, adding: “The reintroduction of administrative detention of minors – not used since 2010 – is a worry trend.”