Two federal lawsuits were filed Friday challenging Indiana's ban on gay marriage.

The lawsuits join two others filed in the last week.

(Related: Second lawsuit challenging Indiana's gay marriage ban filed.)

In one of the lawsuits filed Friday, four married lesbian couples are asking a judge to force Indiana to recognize their marriages.

Indiana Equality, the state's largest LGBT rights advocate, said that the lawsuit, which includes three police officers and a retired firefighter, “focuses, among other denied protections, on the inability of first responders' same-sex spouses to be named as beneficiaries for police and fire pension or death benefits.”

Plaintiffs claim that Indiana's refusal to recognize their marriages violates the Full Faith and Credit clause of the U.S. Constitution.

Fifteen plaintiffs, including two children of gay couples, are involved in the second lawsuit filed by the American Civil Liberties Union (ACLU) of Indiana.

“The government is a power teacher of discrimination,” Sean Lemieux, an attorney working on the case, told The Indianapolis Star. “There is no justification for Indiana to treat these families as second-class citizens. The families in this case want the responsibility, security and dignity that only marriage provides, and their children deserve the same protections that other Indiana families enjoy.”

Indiana Attorney General Greg Zoeller reiterated that his office would defend the state's marriage laws.

“When plaintiffs who disagree with an Indiana statute file a challenge in court, I have a duty as Indiana's Attorney General to defend our state and the statute the Legislature passed to the best of my skill and ability – and will do so here, both now and on any appeal,” Zoeller said in a statement. “Though such cases elicit strong opinions on both sides, Hoosiers should maintain civility and respect toward each other while the court does its work.”

The cases come just weeks after Indiana lawmakers altered the language of a proposed constitutional amendment seeking to define marriage as a heterosexual union, keeping the amendment from reaching voters this November.

Micah Clark, executive director of the American Family Association, a group which opposes marriage equality, blamed lawmakers for the rash of challenges.

“Had the Legislature passed HJ-3 as originally filed and had this been on the ballot this fall, I don't think these lawsuits would have been filed,” he said.