Switzerland. Canton Ticino. Lugano. Ticino State Police, Reparto Intervento Speciali. Special Intervention Unit (SIU). Training exercise with SIU men seeking to capture a menacing, armed man. Three policemen aim their APC-556 machine guns on the wanted man. One shoots at a manikin holding a gun. A police tactical unit (PTU) is a specialised police unit formed and trained to handle situations that are beyond the capabilities of ordinary law enforcement units because of the level of violence - or risk of violence - involved. During the training’s exercice, the police tactical unit intervenes in a high risk situation, such as shootouts, hostage and terrorist incidents. 17.02.22 © 2022 Didier Ruef