BAGHDAD, Iraq (AP) – Explosions went off on the road near Baghdad’s airport Saturday and plumes of black smoke were seen rising from the scene, witnesses said.

The area was sealed off after the blast, witnesses said. The treacherous stretch of the road is the site of daily attacks against U.S. troops and their supply convoys.

It was unclear whether there were casualties in the blasts, which went off near an overpass.

The U.S. military was unable to comment.