Four members of a banned Polish peace and ecology group were fined after protesting in Gdansk against the construction of Poland's first nuclear power plant, an activist in the group said. The four members of the unofficial Freedom and Peace Movement climbed to the roof of a building and unfurled banners reading, "We Don't Want Zarnowiec" and "Freedom and Peace," a Gdansk member said. They also scattered 3,000 leaflets to passers-by demanding that Communist authorities allow a nationwide referendum on the development of nuclear power in Poland. The four were detained by police after they ended their protest. A nuclear plant is scheduled to be completed in Zarnowiec, about 40 miles northeast of Gdansk, in 1991.