A diversion grenade (200) comprising: a transparent body (102) in which is located one or more charges of flash material (104); an internal power supply (114); a control circuit (126) that is responsive to one or more inputs, the control circuit (126) producing one or more output signals; and an external user operated trigger (110) for initiating a user input for activating the grenade (200). The grenade (200) may also include tracer lights (122) and sound emitters (201).