WASHINGTON — Federal raiders. Internet pirates. Intergalactic screen adventures. The government announced a crackdown Wednesday on the theft of movies and other copyright materials that has the elements of a film plot.

Federal agents shut down a Web site that they said allowed people to download the new Stars War movie even before it was shown in theaters.

The Elite Torrents site was engaging in high-tech piracy by letting people download copies of movies and other copyright material for free, authorities said.

The action was the first criminal enforcement against individuals who are using cutting-edge BitTorrent software to obtain pirated content online, Justice and Homeland Security Department officials said.

Elite Torrents had more than 133,000 members and offered 17,800 movies and software programs in the past four months, officials said. Among those titles was “Star Wars: Episode III _ Revenge of the Sith,” which was available through Elite Torrents six hours before its first showing in theaters, the officials said.

The movie was downloaded more than 10,000 times in the first 24 hours.

Authorities served search warrants in 10 cities against computer users accused of being the first to offer copyright materials to other BitTorrent users on the Web site, Homeland Security’s Customs and Immigration Enforcement agency said. The cities are: Austin, Texas; Erie, Pa.; Philadelphia; Wise, Va.; Clintonwood, Va.; Germantown, Wis.; Chicago; Berea, Ohio; Anthem, Ariz., and Leavenworth, Kan.

Authorities said the warrants were still under seal.

Investigators said many of the copyright movies were available through the Web site before their commercial release.

President Bush signed a new law last month setting tough penalties of up to 10 years in prison for anyone caught distributing a movie or song prior to its commercial release.

“Today’s crackdown sends a clear and unmistakable message to anyone involved in the online theft of copyrighted works that they cannot hide behind new technology,” said John C. Richter, acting assistant attorney general.

People trying to access the elitetorrents.org Web site on Wednesday were greeted with a warning about the penalties for copyright infringement, although officials said the investigation is focusing on those who originally offered the pirated materials.

The message also said: “This site has been permanently shut down by the Federal Bureau of Investigation and U.S. Immigration and Customs Enforcement. Individuals involved in the operation and use of the Elite Torrents network are under investigation for criminal copyright infringement.”

BitTorrent has become the file-sharing software of choice because of its speed and effectiveness, especially after the recording industry last year began cracking down on users of Kazaa, Morpheus, Grokster and other established software.

The peer-to-peer software works by using tracker files that are posted online. The tracker files point to users who are sharing a given file, be it a pirated feature film or a home movie. BitTorrent then assembles complete files from multiple chunks of data that it obtains from everyone who is sharing the file.

The Motion Picture Association of America assisted in the investigation that led to Wednesday’s action against Elite Torrents, officials said.

“Shutting down illegal file swapping networks like Elite Torrents is an essential part of our fight to stop movie thieves from stealing copyrighted materials,” said the group’s president, Dan Glickman.

Hollywood movie studios last year sued many operators of computer servers that use BitTorrent technology to help relay digital movie files across the Internet. The group also sued six sites this month that focus on swapping television programs.