Johannesburg: At ​least 12 ​people were killed and ​nine injured on Tuesday evening when gunmen opened fire ‌at an ⁠informal ⁠settlement in Cleveland, east ​of Johannesburg, police said on Wednesday.Police ​said in a statement that they had ​launched a manhunt ⁠for more ‌than 10 ​suspects ​following the attack ⁠at the Jumpers informal settlement.The motive ​for the attack ​is not known.Police said the suspects arrived in a white Toyota Quantum, entered the ‌settlement from two access points and opened ​fire ​at ⁠multiple locations before fleeing in the same vehicle.South Africa has one ​of the world's highest murder rates, averaging about 60 a day.