An Israeli parliamentary committee on Monday advanced a bill that could lead to lack of recognition for conversions to Judaism performed by rabbis from the Reform and Conservative movements.

The bill could give the chief rabbinate, the religious authority in Israel run by ultra-Orthodox Jews, the power to decide which conversions are accepted, overturning an Israeli Supreme Court decision that ensures eligibility for Israeli citizenship for Jews converted by rabbis from all branches of Judaism.

Representatives of the Reform and Conservative movements, which have been battling for years for more rights in Israel, saw the committee vote as a threat to their efforts to strengthen their legitimacy in Israel. The chief rabbinate already holds a monopoly on such rituals as marriage and divorce.

"It sets us back 20 years in terms of the advances that were made," said Rabbi Steven Wernick, executive vice president of the United Synagogue of Conservative Judaism, an umbrella organization of Conservative Jewish congregations in the United States, who spoke by telephone during a visit to Jerusalem. "The practical implication of this bill is one that we are very, very concerned about and angry about."

The bill "delegitimizes most of North American Jewry" and brings back the question of "who has the authority to determine someone's Jewish identity," Wernick added, noting that 85 percent of American Jewry is affiliated with non-Orthodox branches of Judaism.

Also on Monday, police detained for several hours a woman who carried a Torah scroll to the women's prayer section of the Western Wall, one of the holiest sites in Judaism.

Police said that Anat Hoffman, a leader of Women of the Wall, a group that challenges the limitations put on women's prayer at the Western Wall, had violated a Supreme Court ruling that says women cannot read from the Torah in the area.

People who witnessed the confrontation said Hoffman was not reading from the Torah in the prayer area and had only brought it with her. Hoffman was ordered not to pray at the wall for 30 days.

"I've sort of been following it over the years," Mark Greenspan, a Conservative rabbi from Oceanside, N.Y., said of the efforts to scuttle women's prayer at the Western Wall, after watching the confrontation Monday. "I couldn't anticipate how disheartening this was to see this in person."