Mexico's capital legalised abortion yesterday, defying the church but delighting feminists in the world's second-largest Roman Catholic country.
Mexico City lawmakers voted 46 to 19 to pass a leftist-sponsored bill allowing women to abort in the first three months of pregnancy.
The vote split Mexico and prompted a letter last week from Pope Benedict urging Mexican bishops to oppose abortion.
Riot police kept rival groups of rowdy demonstrators apart outside the city's assembly building. Weeping anti-abortion protesters played tape recordings of babies crying and carried tiny white coffins.
"We did it," pro-abortion campaigners chanted after the vote.
The ban will remain in force in the rest of the country and anti-abortion campaigners are likely to challenge Mexico City's abortion law in the Supreme Court.
Only Cuba, Guyana and US commonwealth Puerto Rico allow abortion on demand in Latin America. Many other countries in the region permit it in special cases, including after rape, if the foetus has defects or if the mother's life is at risk.
Leftist deputy Enrique Perez Correa said Mexico was more liberal than its macho image portrayed.
"It appeared to be a conservative country ruled by the Church. We have now shown that is not the case," he said.
Church leaders threatened to excommunicate leftist deputies, mostly from the Party of the Democratic Revolution, who voted in favour of lifting the abortion ban.
"They will get the penalty of excommunication. That is not revenge, it is just what happens in the case of serious sins," said Felipe Aguirre Franco, the archbishop of Acapulco.
Opinion polls show Mexico's population of 107 million, of whom some 90 percent are Catholic, is split over abortion.
Supporters of abortion rights, who are well represented in the capital, say 2,000 women die each year in Mexico due to abortions, often poor women who have to resort to unhygienic back-street clinics.
President Felipe Calderon, a practising Catholic, has largely avoided speaking on the issue but First Lady Margarita Zavala entered the debate at the weekend, condemning abortion in a rare political comment.
Mexico City lawmakers have recently stirred up controversy by allowing gay civil unions and considering a euthanasia law. Further alarming the anti-abortion camp, Mexican lawmakers have filed a proposal in Congress for a national abortion law.
Some 8.6 million people live within Mexico City limits but the whole metropolitan area is one of the world's biggest conurbations, with some 18 million residents.