The suit the group announced Thursday argues that the couples' equal protection rights are being violated because they can't marry in Indiana and the state won't recognize same-sex marriages performed elsewhere.



A similar lawsuit was filed last week by four couples from southern Indiana.



The lawsuits follow Indiana's legislative debate this year on adding the gay marriage ban to the state constitution and multiple court rulings around the country striking down such bans in Kentucky and other states.



Indiana Attorney General Greg Zoeller has said he'll defend the state's marriage laws.