Riot police arrest 15 at New York's Occupy protest

The New York mayor has sent in police in riot gear to remove protestors camped out in the financial district, but they have been told they can return once the area has been cleaned.

At about 1am local time today, police handed out notices from the owner of Zuccotti Park, Brookfield Office Properties, and the city saying that the park had to be cleared because it had become unsanitary and hazardous.

Fifteen people have been arrested.

Some campaigners have apparently chained themselves to trees but reporters are not being allowed into the area.

Protester Angelique Richards has said it is peaceful.

Ms Richards said: "What's happening now is what we call a soft lock and a hard lock; where people stand around the front and lock on to each other.

"Behind them are rows of people who are sitting down with their legs locked around each other and their arms locked around each other."