Same-sex couples in Washington state started taking their wedding vows Sunday on the first day they could marry after the state's new voter-approved law allowing gay marriage took effect this week.

Hundreds of gay and lesbian couples picked up their marriage licenses as early as 12:01 a.m. Thursday, but because of the state's three-day waiting period, the earliest weddings could take place was just after midnight Sunday.

Some courthouses, including in King and Thurston Counties opened right at midnight, and started marrying couples in the early morning hours. Seattle City Hall will open for several hours on Sunday starting at 10 a.m., and several local judges are donating their time to marry couples there.