Fifteen people have been killed and several others have been left in a critical condition in a mass shooting attack in a South African bar.

The police say they are investigating Sunday morning’s attack on a bar in Orlando East, where a group of men arrived in a minibus and opened fire on some of the patrons. 

Those injured in the attack 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 Lieutenant General Elias Mawela.

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

In a separate attack, four other people were killed in a tavern shooting in the south-eastern province of KwaZulu-Natal, police said on Sunday.

“As a nation, we cannot allow violent criminals to terrorise us in this way, regardless of where such incidents may occur,” President Cyril Ramaphosa said, sending his condolences to the relatives of victims of both shootings.

This attack comes two weeks after 22 teenagers died at a tavern in East London, Eastern Cape Province.