Six persons were arrested and two were injured after a mass brawl involving at least 100 youths broke out in London, media reports said.

The Metropolitan police said officials were called to "a large fight" between youngsters in Northumberland Heath in Bexley, south-east London, at about 5.40 pm on Monday, the Guardian reported.

According to speculation on social media, rivalry between school gangs could be the reason behind the fight, some in uniform.

Quoting eyewitnesses, the Daily Mail said the school children "with hoods up and lots with their faces covered up" had knives and bats while, many even took "concrete blocks from a nearby building site to use as weapons".

Local councillor Danny Hackett expressed distress and tweeted: "Concerned about reports of violence and fighting around Northumberland Heath involving youths. Please support @MPSBexley doing their work."

Two individuals, taken to hospital received non-life threatening injuries.