Police have warned the public to dial 999 immediately if they spot a John Howard Centre patient who absconded from the medium secure unit four days ago.

Schizophrenic Ayanda Mpontshane, 24, gave his escort the slip while he was attending hospital for a routine appointment on Thursday.

He was wearing a tag but soon removed it.

Police issued an appeal to trace Mpontshane - who they have warned must not be approached - on Sunday night.

Mpontshane is a black male, aged 24, 5ft 8ins tall, of medium build with short spiky hair and tattoos on his neck and arms.

When last seen he was wearing black jeans, grey T-shirt, green checked shirt and black trainers.

Anyone with information concerning his whereabouts call 999 quoting 2302385/20.

The centre in Kenworthy Road, Homerton, came under the spotlight in 2015 when MPs Meg Hillier and Diane Abbott called for safety to be the "highest priority" after a spate of high-profile offenders - including a violent rapist, child snatcher and the man dubbed "Britain's most prolific burglar" - went on the run while on escorted leave.