Three teenagers stumbled across a suspected wartime bomb as they explored an isolated cove near Aberporth last week.

Eighteen year old Daniel Lewis and his friends George Sommerville, 18, and Robert Thompson, 17, found the rusty object half covered by sand in a cave at Traeth y Gwyrddon, Aberporth.

The trio immediately suspected it was a bomb and Daniel took a video of it with his mobile phone.

"They were absolutely gobsmacked," said Daniel's mum, Diane, of 2 Erw Las, Parcllyn.

"They showed me the video and I just knew it was a bomb. It was as big as a tall gas bottle but fatter and you could see the detonator sticking out."

The coastguard and bomb disposal experts were called out but due to the tides were unable to get into the cave.

"The trouble is that every time the tide comes in so does the sand and covers it up. It is quite worrying to think it could go off any minute," said Diane.

A Royal Navy Bomb Disposal Unit travelled from Portsmouth to Aberporth on Wednesday to investigate the suspected bomb.

The unit was joined by the Gwbert Coastguard rescue team, Cardigan lifeboat and police officers from Cardigan. A search was carried out but at the time nothing was found.

Coastguards say the tide may have covered the device.

"We were looking for an alleged item of ordinance in a cave, but nothing was found. Following reports over the weekend we will investigate the matter again," said a spokeswoman.