Published: 20:08, 11 March 2019
| Updated: 23:24, 11 March 2019
Unusual explosions in the sky may be seen from the Shoeburyness firing range on Wednesday and Thursday from 9am.
QinetiQ, which operates the range on behalf of the Ministry of Defence, has issued a warning of "unusual activity."
Spokesman Nicki Uden said: "We will be carrying out activities which may be visible in the Thames Estuary.
"The activity involves the use of airborne munitions which are designed to illuminate large areas and therefore members of the public may report repeated observations of distress signals or flares or similar up to 3km out to sea."
She added: "All activity on the range is conducted in a strictly controlled environment and presents no danger to the public."
The work is subject to weather and tides and may be subject to change.
If anyone is concerned about the activity, they should call the freephone careline on 0800 0560108.