Three people including a police officer have been stabbed after a spontaneous “water fight” in London’s Hyde Park became violent.

Bottles and other items were thrown at police officers in attendence near the Serpentine as parts of an “increasingly large crowd became hostile” at around 8:40pm.

One police officer was stabbed and another was injured by a bottle, the Met said. Both have been taken to hospital for treatment and their injuries have been described as not life threatening.

Police say they are aware of two other people suffering from stab wounds. Both have been taken to hospital. Their conditions are not yet known.

The violence erupted on the hottest day of the year so far as temperatures reached more than 32C in London.

Videos posted on social media show large groups of young people in the area. In one video, posted by YT_Bricks, shouts of, "They're throwing bottles at Fed cars" can be heard. Another Tweet from Vinnie O'Dowd describes a "riot" in the park.

It is suggested in another post that some of the trouble began after officers told part of the crowd to turn off their music.

Police had been stationed at the Serpentine from 3pm on Tuesday. No arrests have yet been made.

The National Police Air Service say they are continuing flights into the night following the outbreak of violence.