A priest and nine other anti-nuclear activists were arrested at the Nevada Test Site Saturday after conducting religious ceremonies at a former chapel on the top-secret nuclear compound.

Department of Energy spokesman Jim Boyer said 10 demonstrators, including some clergy members, were cited for penetrating the testing grounds - a more serious offense than simple trespassing - and transported to the jail in nearby Beatty.Security personnel were looking for an 11th member of the group, Boyer said.

The incident was part of an annual Easter demonstration called the Lenten Desert Experience, sponsored by the group Nevada Desert Experience, which is opposed to nuclear-weapons testing and the proliferation of the arms race.

Desert Experience spokesman John Klusmire said 11 people ventured onto the U.S. nuclear test site Friday night, taking a roundabout route through the desert to reach the former chapel at Mercury.

He said the anti-nuclear activists reached the former chapel about 4:30 a.m. and conducted religious ceremonies to reconsecrate the building for worship.

The former chapel is now used as an office and storage space. Among those arrested was a Franciscan priest, the Rev. Louie Vitale.

Boyer said no breach of classified security occurred.

"This was not a sensitive area. It is the least sensitive area at the test site," the spokesman said.

Most people who protest at the weapons-testing facility commit a simple trespassing offense by crossing onto government property at the Mercury entrance to the test site. Those people are cited and released.

Boyer said offenders who actually penetrate the site face more serious penalties of being fined and jailed for up to six months.

Nevada Desert Experience began the Lenten demonstrations on Ash Wednesday. Daily activities have been held to mark Holy Week, with activities concluding on Easter Sunday.

Since St. Patrick's Day, about 300 protesters have been cited for trespassing in a series of escalating protests leading up to the Easter demonstration.

Mercury is about 65 miles northwest of Las Vegas. The test site is the center of the nation's nuclear weapons testing program, and 690 announced tests have been conducted there since the installation became operational in the early 1950s.