CCTV footage of gunman opening fire in Brussels Jewish Museum (VIDEO)

Belgium police released the CCTV footage of the gunman who opened fire in the Brussels Jewish Museum Saturday.

The unidentified gunman, donning a baseball cap that concealed his face and carrying a shoulder bag with a Kalashnikov rifle inside, entered the museum around 3:27 p.m. He opened fire through a doorway, killing at least three people. Nearly 30 seconds later, the suspect retreated, New York Times reports.

Two Israeli visitors and one French museum employee were killed at the scene of the attack, and according to New York Daily News, a Belgium museum worker who was in critical condition died at the hospital Sunday.

Officials are still investigating the shooting and say it may have been an anti-Semitic attack. The suspect remains at large and is now the target of a nationwide manhunt.

“We call on the whole population to help identify this person,” said Deputy Prosecutor Ine Van Wymersche. She went on to say the gunman “probably acted alone, was armed, and well prepared.”