WELLINGTON, New Zealand — Police have arrested actress Lucy Lawless and five Greenpeace environmental activists after the group spent four days protesting aboard an oil-drilling ship docked in New Zealand.

Police on Monday removed the group from their perch atop a 174-foot (53-meter) drilling tower on the Noble Discoverer in Port Taranaki. Lawless and six activists climbed the tower early Friday in an attempt to raise awareness about oil drilling in the Arctic.

One of the activists left the tower over the weekend. He was arrested and charged with unlawfully being on a ship.

Chartered by oil company Shell, the ship had been due to leave over the weekend for the Arctic to drill five exploratory wells.

Lawless, 43, a native New Zealander, is best known for her title role in the TV series "Xena: Warrior Princess," and more recently for starring in the Starz cable television series "Spartacus."