Another teenager has been arrested on suspicion of the assault of an off-duty police officer, who was found stabbed in the arm and with human bite marks on his body.

The 38-year-old man was hospitalised on Monday after he was attacked on a football pitch on Wanstead Flats.

A 13-year-old boy was arrested yesterday as Redbridge police continued with their investigation.

Two teenage girls, aged 13 and 16, were arrested on Monday at the scene on suspicion of causing grievous bodily harm.

All three suspects have been bailed to attend an East London police station in late October.

Police said today that no further information was available on the condition of the victim, but he was last said to be in a stable condition in Whipps Cross Hospital in Leytonstone.

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

A number of dog-walkers told the Guardian that they did not feel safe in the area, even before the incident this week.

One walker even said he had heard of young people setting fire to the grass once or twice every summer.