M-Squadron, formerly the Unit Interventie Mariniers, and before that known as the Bijzondere Bijstandseenheid, is an elite Dutch special forces unit which is tasked with conducting domestic counter-terrorist operations. M-Squadron is part of the Netherlands Maritime Special Operations Forces of the Netherlands Marine Corps.

The Netherlands Maritime Special Operations Forces is the special forces unit of the Marine Corps of the Royal Netherlands Navy. It is one of the three principal units tasked with special operations in the Netherlands. The unit can be deployed worldwide to conduct special operations, including counter-terrorism both overseas and domestically, with a maritime focus. Its operations are planned and coordinated by the Netherlands Special Operations Command.