Russian authorities said on Sunday that at least 137 people died as a result of Friday’s mass shooting at a concert hall near Moscow.

According to AFP, the Russian investigative committee said that the death toll from the attack climbed to 137 as of Sunday afternoon, up four from the previous day’s figure. The committee reportedly said that a large amount of ammunition and weapons were found at the concert hall. 

Moscow health authorities said that at least 180 people were injured, 142 of whom were transported to hospital. 

Right after the shooting, the Islamic State group claimed its Afghan affiliate ISIS-K, or the Islamic State Khorasan Province, carried out the attack, releasing footage purporting to show the incident. 

Russian authorities said a total of eleven people were detained on Saturday, including four key suspects. The suspects were transported to the headquarters of the investigative committee in Moscow.