California's Supreme Court has ordered San Francisco to halt the same-sex marriages that have sparked a nationwide debate on whether gay couples can wed legally.
The decision, which will be reviewed again in May or June, comes one month after San Francisco Mayor Gavin Newsom gave the green light to gay marriages, resulting in more than 4,000 homosexual pairings since then.
Mr Newsom said he would comply with the ruling, but city attorney Mr Dennis Herrera said he had filed a new petition with the court last night to determine whether same-sex marriage is constitutional in California.
In its order, the state's top court referred to the California code that defines marriage as a union of man and woman and told San Francisco "to refrain from issuing marriage licenses or certificates not authorized by such provisions."
Governor Arnold Schwarzenegger, who had asked state Attorney General Bill Lockyer to seek a ruling on gay marriages from the Supreme Court, said he was "pleased" at the ruling.
"I believe very strongly that the people should obey the laws that we have here in California," Mr Schwarzenegger said in a statement.
Opponents of same-sex marriage hailed the decision. The mayor "violated his oath and made a mockery of the democratic system," said Mr Mathew Staver, president of Liberty Counsel, which had sued to prevent gay marriages.
But gay-rights advocates said they would continue to fight for the right to wed.