JOHANNESBURG (AP) — A mass shooting at a tavern in Johannesburg’s Soweto township has killed 15 people and left others in critical condition, according to police.

Police say they are investigating reports that a group of men arrived in a minibus taxi and opened fire on some of the patrons at the bar shortly after midnight Sunday.

Those injured have been taken to Chris Hani Baragwanath Hospital.

The number of cartridges found on the scene indicates that a group of people opened fire in the bar, said Gauteng province police commissioner Lt. Gen. Elias Mawela.

“The primary investigation suggests that these people were enjoying themselves here, in a licensed tavern operating within the right hours,” Mawela told The Associated Press.

“All of a sudden they heard some gunshots, that is when people tried to run out of the tavern. We don’t have the full details at the moment of what is the motive, and why they were targeting these people,” he said.

“You can see that a high caliber firearm was used and it was shooting randomly. You can see that every one of those people were struggling to get out of the tavern,” Mawela told The Associated Press.

The area where the shooting took place was very dark, making it harder to find people who could identify the suspects, he said.

Rifles and a 9 mm pistol were used in the attack, said national police spokeswoman Col. Dimakatso Sello.

In a separate incident, four people were shot dead by unknown gunmen at a tavern in Sweetwaters township in the coastal city of Pietermaritzburg on Saturday night.

According to the police, two men entered the tavern and randomly opened fire on the patrons, killing two people on the scene while two others were confirmed dead at the hospital. Police said 8 other people are receiving treatment in a hospital. The deceased were aged between 30 and 45 and police are investigating charges of murder and attempted murder, police said.

“The team will be working around the clock to track down and bring to book those responsible for this shooting”, said Kwazulu-Natal police commissioner Gen. Nhlanhla Mkhwanazi.

South African President Cyril Ramaphosa condemned the two bar shootings.

“As a nation, we cannot allow violent criminals to terrorize us in this way, regardless of where such incidents may occur,” Ramaphosa said in a statement.

“As government, citizens and structures of civil society we must all work together even more closely to improve social and economic conditions in communities, reduce violent crime and stamp out the illicit circulation of firearms,” he said.

The bar shootings come two weeks after 21 teenagers were found dead in a tavern in the city of East London. The cause of those deaths has not yet been announced by authorities, but the teens were not shot nor crushed in a stampede, according to officials.