police car with a long range acoustic device is seen in warsaw, poland on august 7, 2020. several hundred lgbt people and supporters tried to prevent... - long range acoustic device stock videos & royalty-free footage00:08Police break up peaceful LGBT demonstration in Warsaw
protests continue outside the hong kong polytechnic university which has turned into a base for the pro democracy movement with police forces... - long range acoustic device stock videos & royalty-free footage01:37CLEAN : Hong Kong police use water cannons as clashes rage around university campusProtest, Hong Kong
soldiers working on acoustic radar at pine camp / soldier turning, adjusting searchlight / soldier looking through searchlight binocular / long-range... - long range acoustic device stock videos & royalty-free footage00:38US Army conducts military maneuvers at Pine Camp