A man found with knife and bite wounds was a police officer, it has emerged.

Two teenage girls were arrested following reports of an assault and a fire on the football fields at Wanstead Flats at 4.14 pm yesterday.

A 38-year-old man, who police have confirmed is an officer who was off-duty at the time, was found with a stab wound in his arm and a series of human bite marks on his body.

According to reports, he was attacked after he intervened when he saw people trying to start a fire on the field.

Two girls, aged 13 and 16, were arrested at the scene on suspicion of causing grievous bodily harm and taken to a north London police station, where they remain in custody.

The victim is in a stable condition at Whipps Cross Hospital in Leytonstone and police do not believe the suspects and the victim were known to each other.

The fire that was started was extinguished by the fire service at the scene.