Declaring their efforts to ban same-sex marriage far from over, a few hundred opponents of such unions gathered in historic Faneuil Hall on Friday, less than three days before Massachusetts becomes the first state to grant marriage licenses to gay couples.

Thwarted in their efforts to block the implementation of a 4 to 3 ruling by the Supreme Judicial Court last November that deemed a ban on gay marriage unconstitutional, the activists said they would focus their push on amending state and federal constitutions to define marriage as only the union of one man and one woman.

"We want people to know that the fight has just begun," said Kristian Mineau, the recently appointed head of the Massachusetts Family Institute, which helped organize the rally.

The event included an eclectic mix of Christian hymns and patriotic songs, and speeches from political and religious activists, including a Roman Catholic deacon and an Orthodox Jewish rabbi.

Many in the crowd wore yellow stickers that read "Don't tread on me" and said they were angry with the Supreme Judicial Court judges who decided the landmark case. Ralph Briggs, 59, of Redding, Mass., said, "There's a group of people trying to force evil down our throats and defile the constitution."

Outside Faneuil Hall, Patrick Bennison, 42, of Boston, who plans to marry his male partner next year, said he viewed those gathered inside as "the radical fringe, but I came to bear witness. I didn't want it to go unnoticed."

Few large-scale demonstrations are planned for Monday, when the first state-sanctioned marriage licenses will be issued to gay couples here, opponents of gay marriage said.

In Cambridge, which will allow couples to begin the process of applying for marriage licenses at midnight Sunday, local officials have established a zone for protests across the street from City Hall.

A coalition of religious and political groups opposed to same-sex marriage has lobbied vigorously here for months in favor of a constitutional amendment defining marriage as solely a union of one man and one woman. The issue is widely expected to influence statewide elections in November, and Mineau's predecessor, former Georgia lawmaker Ron Crews, is preparing for a congressional bid.

In March, the state legislature gave preliminary approval to such a measure, but included a provision establishing civil unions for gay couples. The earliest that amendment could become law is November 2006.

Opponents of gay marriage, including Gov. Mitt Romney (R), made a series of unsuccessful requests to stay or overturn the state court's ruling. An eleventh-hour bid for a federal court injunction died late Friday, when the Supreme Court rejected a request to intervene.

Citing a 1913 law barring people who cannot marry in their own state from marrying in Massachusetts, Romney has directed town clerks not to grant marriage licenses to same-sex couples from out of state. Some city and town clerks have said they will not turn away out-of-state couples, while the governor said such marriages would be "null and void."

The issue is widely expected to be challenged in court.

In a letter last month to state governors and attorneys general, Romney explained his interpretation of the law and asked to be notified if any other states allowed same-sex marriage.

The office of New York Attorney General Eliot L. Spitzer (D) said Friday it had notified Romney about an opinion issued by Spitzer in March that although gay marriage is illegal in the Empire State, the state would recognize same-sex marriages performed in other states.

But Romney spokeswoman Shawn Feddeman said that because New York couples could not marry in that state, they are not eligible to marry here. A spokesman for New York Gov. George E. Pataki (R) said Pataki shares Romney's view.

Attorneys general in Rhode Island and Connecticut, which do not have laws explicitly banning gay marriage, said they would issue statements Monday about how Romney's interpretation of the 1913 law applies to residents of their states.

Lida Pineda and fiance John DeBach participate in a moment of prayer at Boston's Faneuil Hall. Among the organizers was the Massachusetts Family Institute.