The son of a Boston University professor who had publicly criticized the Bush administration’s handling of the war was killed in Iraq by an explosive device Sunday, according to the U.S. Defense Department.

1st Lieutenant Andrew Bacevich, a 2003 College of Communication graduate, was one of five killed in the attack, and 11 more were wounded, according to the report.

The 27-year-old’s father, College of Arts and Sciences international relations professor Andrew Bacevich, a retired lieutenant colonel, had written op-ed pieces criticizing the war in Iraq and calling for troop withdrawal from the country.

“This is just an unimaginable loss for the family,” said BU spokesman Colin Riley. “The entire university community grieves the loss, not only for professor Bacevich, but for his sisters and mother and colleagues and fellow alums.

“He was just a wonderful young man serving his country,” he added.

Stephen Quigley, an associate COM professor, taught Bacevich in a public relations lab and said he respected him as a person and a student.

“Through the class, I had the opportunity to get to know him reasonably well, and through that experience, I came to admire him very much,” he said. “He was an outstanding young man –¬¬ very strong character, very strong sense of service and responsibility.”

Quigley added that Bacevich was “unusually mature and confident and engaging.”

“I don’t feel like I knew him as well as I wished I had,” he said, “[and] I’m saddened . . . deeply saddened.”

Riley said Bacevich’s parents are creating a fund to honor their fallen son and are requesting donations in lieu of flowers.

Professor Bacevich, who could not be reached, told The Boston Herald on Monday his son “joined the Army to serve his country in a time of need. We love him and mourn his loss.”

Staff reporter Jeannie Nuss contributed reporting for this article.