Iraqi security officials say that militants from the Islamic State group blew up a sports stadium in Iraq's western Anbar province.

The stadium, near the militant-held city of Ramadi, had never been used for sports. In recent months, it was used as a military base for Iraqi security forces and allied militia groups. Security and military officials said Monday the 30,000-capacity stadium was empty when it was destroyed Sunday.

Also in Anbar, officials say the Sunni militant group ambushed a military unit near the city of Fallujah, killing the group's commander, Ali Ahmed, and four of his men.

The officials spoke anonymously as they are not authorized to brief journalists. Iraqi security forces last week announced the launch of a large-scale operation to retake Anbar province from the militants.