Activists of the environmental group Greenpeace strung up an anti-nuclear banner between the towers of the famous Notre Dame cathedral after other members were arrested near a French nuclear test site in the South Pacific. The banner reading ``No to nuclear tests'' was put up at around 11 a.m. Friday and removed without incident about two hours later. Several activists were involved, and no arrests were reported. The environmentalists were protesting the arrest of five Greenpeace members whose inflatable craft entered restricted waters around Mururoa atoll in the south Pacific, where France conducts nuclear tests. They were collecting plankton specimens to determine if they were affected by radiation from the nuclear tests. The captain and four crew members of the Rainbow Warrior II, the craft's mother ship, are being held in French Polynesia. They were to face police charges for illegally entering Mururoa's waters.