Scientologists Open Center in Germany.

Guests from across Europe crowded into a private ceremony Saturday marking the opening of a spacious new center for the Church of Scientology in a country where it is denied recognition as a religion and kept under surveillance.

Police estimated 1,000 people visited the 43,000-square-foot glass and steel building in the capital's western district of Charlottenburg. The U.S.-based Scientology said 4,000 people attended the opening of its Berlin center.

Scientology members packed the sidewalk outside the six-story building, waving their national flags and releasing balloons. The American actress Anne Archer was among the guests of the group, whose members include Tom Cruise and John Travolta.

The opening of such a large center, which Los Angeles-based Scientology said it will use for study, meetings and programs on human rights and the fight against youth violence and drug abuse, has sparked renewed discussion of the group in Germany.

Under surveillance for years by the domestic intelligence service, the Federal Office for the Protection of the Constitution, Scientologists have fought several legal battles with German authorities seeking to end the monitoring.

A Berlin court ruled in 2003 that the group could no longer be monitored by German states, but it remains under the eye of federal authorities.

The German government says it considers Scientology a commercial enterprise that takes advantage of vulnerable people.

The conservative interior minister of the southern state of Bavaria called for increased surveillance of the group's activities in Berlin and across Europe.

"It is indispensable that Scientology be carefully observed in every state," Guenther Beckstein was quoted as saying by the newspaper Berliner Zeitung in an advance from its Sunday edition.

Scientologists reject the government's accusations, saying they are a religion and calling surveillance an abuse of their right to religious freedom.

Archer, who was nominated for an Oscar for her role in the film "Fatal Attraction," said Friday that opponents in Germany were ill-informed. "If people just knew what it is about, that would handle it," she said. "It's just ignorance."

The State Department regularly criticizes Germany in its annual Human Rights Report for continuing to monitor the Church of Scientology despite security officials' acknowledgment they have found no evidence of illegal activity.

German authorities estimate the church has some 5,000-6,000 members in the country, while Scientologists put the number at about 30,000.

In his book "Dianetics," scientology founder L. Ron Hubbard said the "Thetan," or soul, suffers from negative "engrams" implanted in this life and innumerable past lives - though the church avoids the word "reincarnation."

Scientology "auditors" help people work through problems using an "e-meter" device. Members seek a state called "Clear" and then advance through various levels of "Operating Thetan."