The parents of an Indiana man threatened with beheading by the Islamic State group are pleading with his captors to free him, saying in a video statement Saturday that their son has devoted his life to humanitarian work and aiding Syria's war refugees.

Ed and Paula Kassig's video was released a day after the Islamic State group's online video threatened to behead 26-year-old Peter Kassig next — following the beheading of British aid worker Alan Henning.

That video was a heartbreaking development for Kassig's family and friends, who had stayed silent since his capture while working to secure his release.

In the family's video, Ed Kassig says his son, who now goes by the first name Abdul-Rahman after converting to Islam during his captivity, was captured on Oct. 1, 2013, in Syria, where he was providing aid for refugees fleeing that country's civil war.

He says his son has grown "to love and admire" the Syrian people, after growing up in an Indianapolis family with a long history of humanitarian work and teaching.

"Our son was living his life according to that same humanitarian call when he was taken captive," says Ed Kassig, a teacher.

The family says Kassig, a former Army Ranger, formed the aid organization Special Emergency Response and Assistance, or SERA, in Turkey to provide aid and assistance to Syrian refugees. He began delivering food and medical supplies to Syrian refugee camps in 2012 and is also a trained medical assistant who provided trauma care to injured Syrian civilians and helped train 150 civilians in providing medical aid.

His work in Lebanon led to his capture, after which SERA suspended its aid efforts.

Paula Kassig, a nurse, sits next to her husband on a couch in the couple's three-minute video, wearing a head scarf and holding a photo of her son as she speaks directly to him.

"Most of all, know that we love you, and our hearts ache for you to be granted your freedom so we can hug you again and then set you free to continue the life you have chosen, the life of service to those in greatest need," she says. "We implore those who are holding you to show mercy and use their power to let you go."

The family says Kassig served in the Army from 2006 to 2007. He was a member of the 75th Ranger Regiment and served four months in Iraq in 2007 before being medically discharged at the rank of private first class in September of that year, his military record shows.

Kassig focused on humanitarian work after leaving the military. While attending Indianapolis' Butler University, he worked to help refugees from Myanmar who had resettled in central Indiana, said family spokeswoman Jodi Perras.