A closure device for sealing a percutaneous puncture in the wall of a blood vessel includes: an insertion tool having an actuator which is operable in a first mode in which the actuator is configured for deployment of an inner seal inside the vessel and operable in a second mode in which the actuator is configured for tamping a locking member on an outside of the vessel, where the actuator is arranged to be set into the second mode in response to a pulling force acting on a filament connecting the inner seal and the locking member.