A World War Two air raid siren will be sounded over Milford Haven this afternoon as part of a Safe Haven protest about the arrival of LNG in the Haven.

The pressure group will be sounding the siren from Stack Rock Fort; they have taken up residency on the Cadw protected building at the entrance to the Milford Haven waterway, just 500 metres from the controversial LNG jetty.

Safe Haven spokesman, Gordon Main, said they were sounding the siren following complaints from people in the South Hook public information zone that they could not hear the the South Hook COMAH alarm when it was recently tested.

"Residents in the South Hook public information zone have not been able to hear it when going about their normal business," said Mr Main.

"This is a failure of will rather than a failure of technology as our use of a WW2 era siren will demonstrate."

The siren will be tested between midday and 1.30 pm today.

It will sound like a typical air raid siren and will last for about one minute on each sounding.

Members of the public do not need to do anything when they hear the siren.