Authorities are currently investigating an incident that left at least 21 people dead in a South African tavern over the weekend. BBC reports that the victims found inside of the Enyobeni Tavern were between the ages of 13 and 17.

As they work to investigate the cause of death, authorities report that some people attending the tavern, located in the town of East London, were celebrating the end of school exams. A full list of the victims has not yet been disclosed.

South African President Cyril Ramaphosa expressed his condolences on Twitter and extended his deepest condolences to the families of the victims. He also explained that the incident occurred during the country’s observance of Youth Month.

“This tragedy is made even more grave by its occurrence during Youth Month – a time during which we… advocate and advance opportunities for improved socio-economic conditions for the youth of our nation,” Ramaphosa continued.

Oscar Mabuyane, premier of the East Cape province, blamed the deaths on the “unlimited consumption of liquor.” The legal drinking age in South Africa is 18.

“You can’t just trade in the middle of society like this and think that young people are not going to experiment, said Mabuyane from the scene of the tragedy. According to officials, a stampede was out ruled because there were “no visible wounds” found on any of the victims. The incident took place early Sunday (June 26).

The teens were found strewn across floors and tables at the tavern, and a provincial safety official reported that further tests will be conducted to determine the cause of the deaths. “Forensic [investigators] will take samples and test to see if there was any poisoning of sort,” said Unathi Binqose.