BOSTON, Nov. 5 (UPI) -- The Boston-based legal advocacy group that led the fight for gay marriage in Massachusetts is pushing to expand same-sex couples' rights.

Carissa Cunningham, a spokeswoman for Gay & Lesbian Advocates & Defenders, or GLAD, said the group is now setting its sights on the federal Defense of Marriage Act of 1996, the Boston Globe reported Monday.

GLAD has run two ads in publications asking homosexual military veterans who wish to be buried with their spouses at Arlington National Cemetery to contact the group. The ad also encouraged same-sex couples to contact them if they were refused the right to care for a sick spouse under a federal law that allows workers to take unpaid medical leaves.

Cunningham said GLAD has not yet decided whether to file a lawsuit or lobby Congress to repeal the act, but is currently seeking to attack provisions of the law that deny federal recognition of wedded same-sex couples.

"We are not interested in forcing any other state to do anything on marriage laws," Cunningham said in an interview. "We're looking at where (the Defense of Marriage Act) most affects married couples and where the law may be vulnerable."