Hundreds of protesters gathered in Indianapolis Monday in opposition to a proposed state constitution amendment banning same-sex marriage and civil unions.

A Senate committee will take up the issue later this week. The House has already approved the proposal, and the Senate is expected to pass it as well.

The protesters say the amendment would write discrimination into the state constitution.

If approved, the amendment would have to pass again in 2013 or 2014 to be on the state ballot in 2014.

Additional reporting by the Associated Press.