A federal judge deemed Wisconsin's ban on same-sex marriage unconstitutional on Friday to the delight of gay couples who immediately began rushing to county offices to wed as word of the ruling spread.

The ruling marked the latest in a string of decisions by federal judges who have struck down gay marriage bans in a number of states, although the Wisconsin ruling sparked some confusion over whether such marriages could now legally go ahead.

Clerks in two counties were issuing marriage licenses to same-sex couples Friday night, and in response Wisconsin's attorney general filed an emergency motion in the federal court to stay the ruling.