Rescuers walk towards the Ogof Ffynnon Ddu cave system

Brecon Beacons: Major operation under way to rescue injured man trapped in Ogof Ffynnon Ddu cave system for two days

· Sky News

A rescue mission has been launched to save a man who has been trapped inside a cave system in the Brecon Beacons since he was injured two days ago.

The South and Mid Wales Cave Rescue Team said the man fell while caving in Ogof Ffynnon Ddu, a cave system near Penwyllt on Saturday.

The man is unable to climb out of the cave because of the injuries he suffered in the fall.

Cave rescuers gather near the site
The injured caver entered OFD via the Cwm Dwr entrance and is being rescued from the top one

He went inside with a group and one of the people who was with him managed to come out and get help, Sky News understands.

The nature or severity of his injuries is unclear but he has been placed in a stretcher and rescuers are using a device that puts hot air into his lungs.

Peter Francis of the South Wales Climbing Club said he is "fit", with doctors' reports indicating that his vital signs are good.

Ogof Ffynnon Ddu: Britain's deepest cave

At a depth of 309.5m (1,013.8ft), Ogof Ffynnon Ddu (OFD) is the deepest cave system in Britain.

It is also the third-longest, stretching for 60.6km (37.6miles) under the Brecon Beacons in South Wales.

The cave system is a Site of Special Scientific Interest (SSSI) and owned by Natural Resources Wales, which is part of the Welsh Government.

There are five entrances to OFD, which are all gated and only accessible with keys given out by the South Wales Caving Club (SWCC).

SWCC only give out keys to permit holders, who have to be members of caving clubs that are affiliated to the British Caving Association (BCA) or equivalent national body.

Groups of cavers granted access to OFD are limited to groups of no more than six and must have "adequate experience and suitable clothing".

SWCC stresses that cavers "enter at their own risk" and "many sections of the cave are arduous".

They also do not monitor the caves, so groups "must make their own arrangements for rescue".

Between 2,000 and 2,500 trips are made to OFD by cavers every year, mostly at weekends, according to SWCC.

The caver currently stuck due to his injuries entered the site through the Cwm Dwr entrance and is being brought out by a team of at least 242 rescuers at the top entrance, Sky News correspondent Becky Johnson reported from the scene.

"He is holding up very well," he said, "and we are very optimistic."

Mr Francis said the hope is that he will be extricated today but he is not sure if that will happen.

Rescuers have been focused on keeping him warm so he does not catch hypothermia.

Mr Francis said getting him out could take a long time because the route is "like a maze" and needs to rigged.

Rescuers congregate as a man has been injured and trapped in the cave system since Saturday

"The worst thing that could happen is that we dropped him in the stretcher or something like that and injured him even more," he said. "So we've got to safeguard him in advance."

The South and Mid Wales Rescue Team said in a statement: "The incident has continued during the night.

"We are moving the casualty towards the top entrance of the cave, which is located up on the mountain behind Penwyllt."

At least eight rescue teams from across the UK have joined the operation, including the Gloucester Cave Rescue Group, Midlands Cave Rescue Organisation, Derbyshire Cave Rescue Organisation, Mendip Cave Rescue, South East Cave Rescue Organisation, the Cave Rescue Organisation, and Upper Wharfedale Fell Rescue Association.

An ambulance was among the vehicles on the scene

At midday, Sky's Becky Johnson was told there were 242 people involved in the effort.

Located inside a nature reserve, Ogof Ffynnon Ddu - meaning Cave of the Black Spring - was discovered in 1946 and is 300m deep at its lowest point, with its underground caverns stretching over 30 miles.

Only experienced cavers are granted permission to explore inside.