British police trying to evict protesters at a London Olympic site say they have arrested four people.

Metropolitan Police said Tuesday that officers faced about 30 protesters blocking access to the building site of a basketball training camp in Leyton Marsh, northeast London.

A High Court judge ruled last week that the protesters must be removed soon to allow builders to work on the site.

The protesters, some belonging to the Occupy London movement, have set up a camp and blocked building work there because they fear that construction will close off the green space to the public.

But the Olympic Delivery Authority has insisted the basketball training facility is a temporary structure that will be dismantled after the games, which take place from July 27-Aug. 12.