Durban – Four toll booth operators have been injured in violent attacks at the Mvoti Toll Plaza in KwaDukuza, north of Durban, on Tuesday. The plaza has been left unattended.According to the police, the operators' colleagues allegedly assaulted them.ALSO READ: Residents block roads in protest over KwaMashu taxi driver's killingPolice spokesperson Lieutenant Colonel Thulani Zwane said 50 protesting toll workers, who are believed to be members of the South African Transport and Allied Workers Union (Satawu), used tyres, tree logs and rocks to barricade the part of the N2 freeway where the plaza is situated.Zwane said a structure at the toll plaza was also burnt, which resulted in a case of malicious damage to property being opened at the KwaDukuza police station."The protesters were apparently demanding [an] increase in salaries. SAPS KwaDukuza managed to disperse the unruly mob. [There were] no arrests or injuries. A case of public violence is being investigated by KwaDukuza SAPS."ALSO READ: Numsa to march against new labour laws on Human Rights DaySatawu members also shut down several toll plazas between Mthunzini and Marianhill on Monday, as part of their protest.IPSS medical rescue spokesperson Paul Herbst said that, while police were on scene, the toll booth was "open and free flowing".Herbst said IPSS treated the four operators.