The mayor of Amsterdam married five American-Dutch gay couples in an implicit criticism of the lack of same-sex marriage in many states.

Tens of thousands of spectators cheered as Mayor Job Cohen performed the ceremony on a cruise around the city's canals to celebrate the high point of the city's gay pride festival. Eight years ago Mr Cohen presided over the first legal Dutch gay marriage.

All five couples had at least one partner from New York, where a battle over the legalisation of gay marriage rages on. "For me it's a message to New York, the most liberal state, the most hip state, to get with it," said Ira Siff, an opera professional from New York who was about to marry his partner, opera singer Hans Heijnis.