MONTPELLIER, France » In a historic ceremony broadcast live on French television, the first gay couple to marry in France said "oui" then sealed the deal with a lengthy and very public kiss.

Hundreds of invited guests including a government minister gathered for the ceremony today inside city hall in southern French city of Montpellier. Hundreds more flocked to the square outside the building as Vincent Autin, 40, and his 30-year-old partner, Bruno Boileau, were wed.

The politically charged ceremony was held under tight police surveillance — a stark reminder of the months of bruising opposition to the new gay marriage law that French lawmakers passed earlier this month.

Police today used tear gas to scare away a small group of protesters who gathered behind city hall.

"Even if we have passed the hurdle of equality, there are still more battles to fight… But for now, it’s a moment for festivity, for love," Autin said after exchanging vows.

The two men then walked hand-in-hand to the city hall balcony to wave to well-wishers alongside Montpellier Mayor Helene Mandroux, who officiated at the ceremony. Smiling proudly, Mandroux called the marriage a "historic moment" and "a stage in the modernization of our country."

The two men, who will adopt the names "Messieurs Bruno et Vincent Boileau-Autin," were holding a separate, private ceremony later today for close friends and family.

"Many people have been waiting for this law on marriage and adoption. Now, it’s done. Many people are going to be doing as we did, and celebrating their unions… We are very pleased and honored," said Boileau.

It is not clear yet when the first gay adoption will take place.

News of the marriage will not be welcomed in every corner of France. Just last Sunday, tens of thousands of people protested fiercely in Paris against the new gay marriage law, demonstrations that ended with riot police shooting tear gas.

A plan to legalize same-sex marriage and allow gay couples to adopt was a liberal cornerstone of Socialist Francois Hollande’s election manifesto last year. It initially looked like a shoo-in for the French president — since the measures were supported by a majority of the country — and an easy way to break with his conservative predecessor, Nicolas Sarkozy.

But the issue became a touchstone as Hollande’s popularity sunk to unprecedented lows, largely over France’s ailing economy. The law became a political hot potato that exposed bitter divisions between urban France, where homosexuality is widely accepted, and the Catholic heartland where conservative attitudes hold sway.

"What happened in our country to create so many divisions?" Mandroux wondered aloud today, reflecting on the wrenching debate.

Demonstrations against the gay marriage law have often spilled into violence.

In Sunday’s protest in the French capital, several hundred protesters clashed with police, throwing bottles and chasing journalists. Interior Minister Manuel Valls said police arrested some 100 far-right protesters.

Paris police estimated that 150,000 people took part in the demonstration but march organizers claimed on their Twitter account that more than a million people did.

At the same time Sunday, on the shores of the Mediterranean, the prestigious 66th Cannes Film Festival gave the Palme d’Or, its top honor, to "Blue is the Warmest Color: The Life of Adele," a graphic French film about a tender, sensual lesbian romance.

France is the 14th country so far — and the biggest in political and economic weight — to recognize gay marriage.

Thomas Adamson reported from Paris.