A stampede at a military stadium has left at least 37 people dead in Republic of Congo after large crowds of young people responded to a recruitment appeal, authorities said Tuesday.

Public prosecutor Oko Ngakala said that an investigation would be launched and questioned why the event was still going on at midnight.

Brandon Tsetou, a young graduate who escaped the suffocation, said he had been lined up in front of Ornado stadium since Monday morning.

“According to the organisers, it was the last day. That’s why many of us decided to wait until late into the night, hoping to register,” he told The Associated Press. “Some were so impatient that they had to force their way in, causing a stampede that left a number of people dead or injured, which we deplore.”

Long lines have formed outside recruitment centers each day over the past week as young people have sought to join the army, one of the few institutions offering work in Republic of Congo. As many as 700 people a day have registered, though there are only a total of 1,500 places available.

“The provisional toll established by the emergency services is 37 dead and many injured,” according to a press release issued on Tuesday by the prime minister’s office crisis unit.