8 August 2012 Last updated at 15:01 ET

New Quay beach temporarily closed after shark alert

This footage of the shark was filmed by Jasmine Jones from her boat, who also described what she saw

Holidaymakers were advised not to swim in the sea near a beach after a shark was spotted by RNLI lifeguards.

Red flags were raised on New Quay in Ceredigion at 17:25 BST on Tuesday, after the creature, believed to be a blue shark, was spotted in shallow waters yards from the beach.

The beach reopened on Wednesday. The RNLI said it was extremely unusual to see a shark so close to the shoreline.

It swam between boats moored at the end of the beach behind the breakwater.

"I first saw a big shadow of a shark and then it came up a bit and was swimming around," said Jasmine Jones, who spotted it from her boat.

"It was only a few metres from the sand and it was in really shallow water about half a metre deep.

"It was a bright blue in colour with really round eyes, not beady - they were huge," she added.

The creatures feed on other fish, such as mackerel, herring and squid.

In 2005, a Welsh record was set 25 miles off the coast of Milford Haven, when a fisherman measured a blue shark at 271cm.