Two lesbian brides and six gay grooms became the world's first homosexuals to wed legally, tying the knot on Sunday in a colourful communal ceremony.

They married minutes after a Dutch law allowing same-sex matrimony came into effect.

The four couples plighted their troth in the rose petal-bedecked city hall of Europe's gay capital, Amsterdam, to the cheers and whoops of family and friends - some clad in tight black leather, others in sedate frocks and picture hats.

"You are writing history," Mayor Job Cohen, who officiated, told the couples just after midnight ushered in the new law.

"This is the first civil marriage to be celebrated between two women and two men. That is unique in the world."

The Dutch parliament passed the gay marriage law - fiercely opposed by Christian parties - late last year, along with legislation allowing homosexuals to adopt children.

The Netherlands had offered gays "registered partnership" since 1998, which allowed same-sex couples to regulate their relationship legally in a way largely like marriage.

But a desire to offer the symbolism of marriage to all, whatever their sexuality, drove the move to legalise homosexual unions in a country that sets the global pace in gay rights.

Driven to the city hall in a motorcade of candy-coloured Volkswagen Beetles, the couples arrived waving and grinning, unruffled by seven soberly-dressed Christian protestors holding placards urging: "Come, let us return to the Lord."

"We want people to choose an alternative, we want to show them this is a much better way. We believe true fulfilment lies in God, not in the satisfying of their lusts," Frans Gunnink of Christians for Truth said.

But for Louis Rogmans, 63, about to wed his 72-year-old partner Ton Jansen, nothing could spoil the moment.

"We've asked people not to bother buying us presents. It sounds corny but this is the biggest present we could have," said Rogmans, who like his boyfriend of 36 years sported a tuxedo and pink bow tie.

Asked what he expected of their wedding night, Jansen said: "After so many years together it'll just be a normal night."

Pink champagne

Long-stemmed roses in vases and a giant heart made of pink and red rose petals enlivened the austere conference hall normally used for meetings of the city council's great and good.

The bridal couples, all of them already legally registered partners, stood as the mayor asked each in turn: "Will you convert your partnership into a marriage and do you swear to fulfil all the duties with which the law endows marriage?"

After saying "I do", three of the couples exchanged rings.

Social worker Peter Wittebrood-Lemke and schoolteacher Frank Wittebrood chose to seal their union instead by removing gaudy rings - to reveal ring designs tattooed on their fingers.

The toast was drunk in pink champagne. The wedding cake, iced in shocking pink, bore eight figurines - three male couples and one female. It was no ordinary wedding.

But lesbians Helene Faasen and Anne-Marie Thus were keen to stress that theirs was no different from any other marriage.

"We're not pioneers. We're just grateful we've been able to do this. Now we just want to live a normal family life," said Faasen, pushing back an ivory veil and clutching a posy of white roses that complemented her new wife's peach-coloured bouquet.

Faasen's father, Peter, said she had made him proud. But he was sorry there would be no church wedding. "I'm a Catholic and with this Pope that's never going to happen," he said.

Amsterdam chief registrar Evert Geuzinge said he expected the Netherlands would now see around 10,000 gay weddings a year, or 10 percent of the average annual marriage total.

© Reuters