Luxembourg's prime minister has married his civil partner, becoming the first serving leader in the European Union to marry someone of the same sex.

Xavier Bettel, 42, and Belgian architect Gauthier Destenay were among the first men to marry under a new law, introduced in Luxembourg in January, making it the latest on nearly a dozen EU states to allow same-sex marriage.

Following the private ceremony at city hall the couple were greeted by crowds of well-wishers.

Mr Bettel hugged Mr Destenay and said: "Luxembourg can set an example."

Fellow EU prime ministers Charles Michel, 39, of neighbouring Belgium, and Estonia's Taavi Roivas, 35, attended the civil ceremony conducted by Mr Bettel's political ally and successor as mayor of the city of Luxembourg.      

Mr Bettel, a lawyer by training, publicly came out as gay in a radio show seven years ago.

He became prime minister in December 2013, ending 19 years in power for Jean-Claude Juncker, who now heads the European Commission in Brussels.

Five years ago, Johanna Sigurdardottir, the then the prime minister of Iceland, became the first serving government leader in the world to marry a same-sex partner.