Five people have been charged after a protest at the Sydney Opera House today, police say.

Shortly before 10am, police from The Rocks Local Area Command were alerted to a number of people trying to access the sails of the building.

Forest activists drop a large banner off the roof of Sydney Opera House in a protest against retail giant Harvey Norman.

Two women were arrested after allegedly refusing directions by security officers to leave the area.

They were both charged with trespass.