Multiple gunmen opened fire at a Moscow concert hall Friday, leaving at least 40 people dead and more than 100 people injured, Russia’s Federal Security Service said.

Video footage from the Crocus City Hall music venue near Moscow shows at least three gunmen dressed in camouflage clothing firing automatic weapons. The Associated Press reported that assailants also threw explosives, creating a large fire.

Fifty ambulance crews were sent to the scene, as well as police and firefighters, Reuters reported, citing Russian news agencies.

In one video posted on social media, gunmen were filmed shooting at civilians near the hall’s entrance sign. Other footage showed multiple people lying on the ground in a pool of blood. ... Read More: The Hill