( CNN ) -- Public transport in the Belgian capital , Brussels , was paralyzed for a fourth day Tuesday after staff walked out to protest the death of a co-worker in an assault . Guy Sablon , a spokesman for the company that runs the Brussels public transport network , STIB , told CNN there are no buses , trams or trains operating in the city . The workers have demanded new security measures to keep staff safe . The city 's transport network was shut down Saturday after a traffic accident involving a car and a bus led to a fatal assault . Sablon told CNN that a friend of the car driver had punched an STIB supervisor who was taking pictures of the accident scene . When the man saw the supervisor taking the photographs , `` he completely lost it , '' Sablon said . `` He then punched him in the face , and unfortunately this punch killed the supervisor . '' Sablon said the attack was not an isolated incident . `` Every day , our staff suffer aggressive abuse from clients , so they have unfortunately gotten used to aggressive situations , '' Sablon said . `` Therefore , we have endorsed this strike and demanded measures from the government . '' Both the Belgian government and the STIB announced new measures Monday evening . STIB announced that it will recruit 50 new security officers , on top of the 190 officers it already has . As a short-term response , it will also move some of its staff from duties such as checking tickets to security roles . The government also announced that it would hire 400 new police officers , dedicated to working on the public transport network . `` Now the unions have to explain these measures to their members . We had hoped that they would be back at work this morning , but they were not ready to return to work . So we will see how long the strike will last , '' Sablon said . `` These are very good measures , and they will have a big impact . It will just take some time to implement them , '' he added . Brussels is home to NATO , the European Commission and European Council , as well as many other international organizations .
A transport company supervisor resigned after he was punched by a member of the public . Striking transport workers want authorities to give them more protection . Their company and the Belgian government say they will hire new security guards . Brussels is home to NATO , the European Union and many other international groups .