One provision makes it illegal for a woman to resist her husband’s sexual advances. A second provision requires a husband’s permission for a woman to work outside the home or go to school. And a third makes it illegal for a woman to refuse to “make herself up” or “dress up” if that is what her husband wants.

The passage of the law has amounted to something of a historical irony. Afghan Shiites, who make up close to 20 percent of the population, suffered horrendously under the Taliban, who regarded them as apostates. Since 2001, the Shiites, particularly the Hazara minority, have been enjoying a renaissance.

Image Some women in Kabul chanted in support of a new family law for the Shiite minority that permits marital rape, among other things, and applies other restrictions. Credit... Robert Nickelsberg/Getty Images, for The New York Times

President Karzai, who relies on vast support from the United States and other Western governments to stay in power, has come under intense international criticism for signing the bill into law. Many people here suspect that he did so to gain the favor of the Shiite clergy; Mr. Karzai is up for re-election this year. Previous Afghan governments, during the Soviet era and before the arrival of the Taliban, did not impose such restrictive laws, although in practice many rural women’s freedoms have long been curtailed. Rights advocates say the law for Shiites could influence a proposal for Sunnis and a draft law on violence against women.

Responding to the outcry, Mr. Karzai has begun looking for a way to remove the most controversial parts of the law. In an interview on Wednesday, his spokesman, Homayun Hamidzada, said that the legislation was not yet law because it had not been published in the government’s official register. That, Mr. Hamidzada said, means that it can still be changed. Mr. Karzai has asked his justice minister to look it over.

“We have no doubt that whatever comes out of this process will be consistent with the rights provided for in the Constitution  equality and the protection of women,” Mr. Hamidzada said.

The women who protested Wednesday began their demonstration with what appeared to be a deliberately provocative act. They gathered in front of the School of the Last Prophet, a madrasa run by Ayatollah Asif Mohseni, the country’s most powerful Shiite cleric. He and the scholars around him played an important role in drafting the new law.