The Directorate of special units (DSU) (Dutch: Directie van de speciale eenheden; French: Direction des unités spéciales; German: Direktion der Sondereinheiten)[1] is the police tactical unit of the Belgian Federal Police.

The centralized 50 operator small assault team of the intervention unit of the DSU is deployed in cases of terrorism, kidnappings, hostage taking and other forms of serious crime.

[3] In 1974 the name was changed from Diane to SIE (also outside Belgium, Dutch: Speciaal Interventie Eskadron) or ESI (French: Escadron spécial d'intervention, also known as Groupe interforces antiterroriste).

[1] On March 18, 2024, DSU officers were targeted by an arms and drug trafficking suspect during a search in Lodelinsart, Charleroi.

There are four decentralised units, called "Protection, observation, support & arrest platoons" (POSA), spread over the country:[1] Overall control of the DSU lies with the Ministry of Internal Affairs, but depending on circumstances the unit can be deployed under operational control of the Ministry of Justice.