21. At least one expert said the cannisters probably weren't the source of the fire, however. 22. Subsequent journeys will have as many as six times as many glass cannisters , the industry officials said. 23. Police through up a cordon around the station and fired tear gas cannisters to drive the crowd back. 24. When you pull the mask, it activates the detonator; the ensuing fire in the cannister produces oxygen. 25. The troops, who are equipped with riot control gear, fired tear gas cannisters to drive them back. 26. The M-651 CS cannisters can be shot from an M-79 grenade launcher, Cutshaw said. 27. A police in a blue uniform bomb expert at the scene carried away three unexploded cannisters wrapped in nails. 28. The cannisters -one red, one blue and one green-were believed to be a makeshift bomb. 29. The pits confine the explosive plutonium inside steel jackets, and each pit is delicately suspended inside a cushioned cannister . 30. The cannisters aren't pressurized and so won't explode from changing cabin or cargo-hold pressure.
