Killing a member of the South African Police Service (SAPS) should be considered an act of treason, Police Minister Bheki Cele said on Thursday."Killing police is treason because you are attacking the State. If you kill police, you must accept that your life will be difficult," Cele warned.The minister was speaking at a memorial service in Cape Town where he and National Police Commissioner General Khehla Sitole paid their respects to three police officers killed last week.ALSO READ: Two Cape Town cops killed in one night, firearms takenConstables Lonwabo Kili and Siyamcela Ncipa were shot and killed in separate attacks on Friday.On the same day, Constable Arthur Mantu's charred remains were found in his vehicle."South Africans are safe because police are safe. Killing police is beyond the scope of criminality. It is reactionary politics because it tells South Africans that they are not safe."He added that deadly force should be used if a suspect posed a threat of serious violence to a police officer or a member of the public.'You must use deadly force'"You will be protected if you work within the law. Section 49 of the Criminal Procedure Act is very clear on this," he said to the police officers in attendance."If your life is in danger, you must use 'deadly force' – that's the word."He said that his plan to arrest the murder suspects had not been abandoned, despite the lack of arrests.Last week, Cele issued a 72-hour action plan to ensure the arrest of those behind the murders of Kili and Ncipa, and the recovery of their stolen firearms.Sitole took exception to the fact that Kili and Ncipa were robbed of their firearms."Never allow yourself to be undermined. Use your training and equipment provided to you," he said."If a confrontation happens and you go down, die with your gun. It is more important to live for South Africa than to die for it."