Belgian police released new images Thursday of “the man in the hat”—one of the suspects in last month’s Brussels Airport bombing—in an effort to track him down. The man was dressed in light colors and wore what appears to be a dark bucket hat while pushing a luggage cart in highly circulated footage with two other men, in the minutes before their suicide bomb exploded. The other men were identified as Najim Laachraoui and Ibrahim El Bakraoui, who blew themselves up in the attack. The new images are from surveillance video and feature the man walking by the nearby Sheraton hotel and Avis rental lot. Later, he was seen in Zaventem without his jacket. Prosecutors are asking for help in tracing the man’s escape route from the attack, adding that they’re hoping for any photographs of him.