Wiltshire Police are investigating an explosion at Chemring Countermeasures defence plant near Salisbury in southwest England that killed one person and left another in critical condition. The explosion occurred in the plant’s flare manufacturing building just after 5pm on Friday, prompting an immediate evacuation. Chemring Countermeasures is part of the Chemring Group. The plant produces flares, chaff and decoys to protect military and civilian air and sea platforms.