In the run up to tomorrow's Bonfire Night celebrations H.M. Coastguard is warning members of the public that it is an offence to use distress flares as fireworks.

"Red flares are a means of raising the alarm and attracting attention for those in trouble at sea, in estuaries or on navigable rivers," said a spokesman from Milford Haven's coastguard headquarters.

"They are spectacular when fired, going up to 1000 feet into the air, bursting at the top of their trajectory into one single bright red glow which appears to slowly spiral earthwards in approximately 30 seconds.

"You might think flares are a great way to give a fireworks party a wow factor," she continued, "but it is an offence to use a distress signal, flare or other distress pyrotechnic on land, in a harbour or at sea, either for testing purposes, practice or as a firework." The spokesman added that the legislation also applied to out of date flares, which can be unstable explode unexpectedly , causing severe injuries. Flares past their use by date should never be fired but should be handed in either to a maritime chandler or to the coastguard.

If you are caught using flares as fireworks and prosecuted under merchant shipping laws you can face a heavy fine.

"Remember if your flare is seen and reported to the emergency services you may put someone else's life in danger, diverting vital services like lifeboats and coastguards away from real emergencies and to your firework party," said the spokesman.

"Have fun on Bonfire Night but with proper fireworks, never ever flares."

Milford Haven coastguard HQ are also asking anyone who is planning a firework party near the coast or on the Cleddau to let them know by dialling the 24 hour contact number 01646 690909. Notification of such events in advance should minimise the risk of false alarms.