Dog-walkers say they do not feel safe in the park where an off-duty police officer 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.

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

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

A woman was sexually assaulted in nearby Hollow Ponds while out jogging earlier this month. The attacker remains at large.

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

Danny Brown, 56, who lives in East Ham but travels every day to the park to walk his dog, said people were choosing to stay away after reports of crime.

He said: “The numbers of dog-walkers are dwindling fast here and it is these sorts of incidents that are causing it.

“A couple of months ago I heard there was a few women robbed and I do feel I have to be on my guard here now."

Bronwen Baker, 39, from Chestnut Avenue, Forest Gate, shared Mr Brown’s concerns.

She said: “You hear of a few incidents like this and it does worry me. There are a few dodgy characters that you have to give a wide berth.

“It is true, I am more wary when I walk my dog in the park, though that hasn’t stopped me coming here every day. The park is pretty open so there is good vision of spot anything unusual."

Noresh Das Gupta, 57, of Ridley Road, in Manor Park, said he had heard of young people setting fire to the grass in the park.

He said: “I have heard of kids setting fire to logs around this time of year. You hear reports of it once or twice in the summer.

“The grass gets very dry and they probably just want to see the fire brigade turn up and put it out.

“But I have never had a problem in the park and it is quite incredible that these young girls could have done this.”