Johannesburg - Two suspects arrested after a failed Uber hijacking, may be linked to other cases in which Uber drivers were either hijacked or robbed. On Sunday morning the two suspects requested an Uber from Roodepoort to take them to Pretoria. While on route to Pretoria, the suspects requested that the Uber driver pick up a third person at the Flora clinic. Once there, they tried to hijack him, according to police. “[They] took out sharp objects and threatened him and instructed him to get out of the vehicle. He started pressing the hooter to attract other motorists. That's when the suspects fled and got into a taxi,” said police spokesperson Captain Kay Makhubela.Makhubela said the Uber driver followed the taxi and alerted a security company who proceeded to follow the taxi as well. Once the taxi was stopped, the two suspects fled on foot. The security guards apprehended them a short while later. Makhubela said police are currently trying to see whether the two suspects can be linked to other cases where Uber drivers were either hijacked or robbed.Already, looking at the modus operandi, police have managed to link one of the suspects to another case where an Uber was requested and then the driver subsequently robbed. Severe chemical burnsIn another incident, during the early hours of Sunday morning, an Uber driver sustained serious chemical burns after his passenger poured acid on his face.Makhubela said the man was responding to a request for an Uber ride at Waterval Estate in Northcliff, Johannesburg. He was travelling in a Toyota Corolla from Sophiatown."When he arrived at Waterval, the man poured acid on his face and threw him out of the car. The man [the assailant] sped off, [in his own car]" Makhubela said.ER24 paramedics spokesperson Werner Vermaak said they found the man on the side of the road on Milner Street in East Town, Johannesburg, at around 02:00.He had sustained severe chemical burns to his face and hands."According to the man, he arrived at his drop off location and was assaulted by his passenger and [a] liquid substance was thrown onto him,” Vermaak said.He was rushed to hospital.Makhubela said they would wait until the Uber driver was discharged from hospital and see if he could identify his attacker as one the two suspects arrested on Sunday.Uber spokesperson Samantha Allenberg confirmed they were aware of the incident, saying it was deeply upsetting.Allenberg said that while there have been conflicting reports about the incident, they were working closely with police.