Sikh leaders have been excluded from an upcoming interfaith meeting with Pope Benedict XVI during his visit to the United States because their ceremonial daggers were forbidden by the Secret Service, the Washington Times reports.

The April 17 meeting is scheduled to take place at the Pope John Paul II Cultural Center near Catholic University in Washington.  The meeting originally included Sikhs along with Jewish, Hindu, Muslim, and Buddhist guests.  A list released on Tuesday by the U.S. Conference of Catholic Bishops substituted followers of another India-based religion, the Jains, in place of the Sikhs.

Ten to 15 Sikhs were to attend the papal meeting.  Most of them were veterans of a Catholic-Sikh dialogue begun in 2006.

Sikh leaders say that the Secret Service had forbidden them to wear the “kirpan,” a dagger that all Sikhs are required to wear.  Sikhs have compared its importance to their faith with the Orthodox Jewish requirement that men wear a yarmulke.

Anahat Kaur, secretary general of the World Sikh Council, America Region, said that Pope John Paul II met with kirpan-bearing Sikhs at the Vatican in January 2002. 

"We were pretty disappointed," Kaur said, speaking about the prohibition of the kirpan. "At an event meant to promote understanding between faiths, we would have had to renounce a fundamental tenet of our faith to attend.”

Kaur said that the Secret Service had the opportunity to investigate the guests and evaluate their safety.  “We thought that would be enough,” she said.

"We have to respect the sanctity of the kirpan, especially in such inter-religious gatherings,” Kaur said in a separate press release. “We cannot undermine the rights and freedoms of religion in the name of security.”

Eric Zahren, a spokesman for the Secret Service, said that no weapon could be allowed within striking distance of a head of state.

"We have every respect for it as a religious artifact," Zahren said, according to the Washington Times, "but it's by definition a weapon even though that is not the intended use. And we have to answer for the security of the Holy Father while he is here."

Sister Mary Ann Walsh of the U.S. Conference of Catholic Bishops said the conference feels "bad about this" but that the groups involved "came to an impasse."

According to Kaur, kirpans are only used in self-defense as a last resort.  In 2004 a Sikh leader was refused admittance to the White House when he refused to give up his kirpan.  In 2006, Sikh representatives were also refused entrance to the European Union parliament in Brussels.

There are about 20 million Sikhs worldwide, making Sikhism the world’s fifth largest religion.  There are about 250,000 Sikhs in the United States.