Trapped miners: Bid to rescue men in Swansea Valley
A major rescue operation is continuing after four miners became trapped by water in a small mine in the Swansea Valley.
About 50 rescuers are trying to free them from a ventilation shaft at Gleision Colliery near Cilybebyll, Pontardawe.
Two men escaped, and a third was taken to hospital. No details have been released about his condition.
Police said water had to be drained from the mine.
The Mines Rescue Team leader Andrew Watson said no contact has yet been made with the miners, who were trapped by water after they broke into an area of old mine workings.
Rescuers have taken in lights and pumps and are trying to work out how much water is there and whether it is getting deeper in the mine, which is near the River Tawe.
They are said to know where the miners were working but they do not know where they are now.
Supt Phil Davies said though there was water in the mine, there was nothing preventing access.
"There is not a blockage issue in the mine, it is a water issue which we are currently trying to drain," he said.
"We are dealing with a difficult rescue operation but we are doing everything possible."
He said it was too early to say what had caused the incident.
"It's a very difficult circumstances for everybody, in particular the family and friends of those who are trapped," he added.
"The situation is changing on a regular basis."
Emergency services were called to the mine at 09:21 BST.
One miner who was rescued is in Morriston Hospital, Swansea, but his condition is not known.
Two more men escaped unaided from the drift mine - a mine cut into the side of a hill where the coal seam is accessed horizontally - before emergency services arrived.
They were giving rescuers "a lot of information about what has happened".
Supt Davies would not comment on reports that the colliery owner was one of the trapped men.
Friends and relatives are being kept informed by police family liaison officers.
Health and Safety Executive inspectors are heading to the site and will be investigating alongside police.
BBC Wales reporter Nicola Smith said about 50 rescuers were involved, of whom 18 to 20 were firefighters trained for this type of incident.
Rescuers include nine rope specialists and 12 urban search and rescue specialists.
The Mines Rescue Service (MRS) in south Wales, which sent a team of five rescuers to the colliery at 09:45 BST, said there had been no explosion or fire.
Local councillor Arthur Threlfall said: "I understand the injured man was taken to hospital via helicopter.
"The mine is in quite a remote spot. At the moment you cannot go anywhere near it because a large area around it has been cordoned off by the police."
He added: "Gleision is one of those collieries that has open and shut many times, and they tend to work on the basis of when coal is found. However, it has recently been extended.
"This is the first mining disaster I have known for many years. There are not many collieries left like there used to be.
First Minister Carwyn Jones said he was being kept fully informed of developments.
"As someone with very strong family links with both the Swansea Valley and the mining industry, my thoughts and prayers - and those of the people of Wales - are with the trapped men and their families at this difficult time," he said.
"My main priority and the priority of my government is to ensure that those trapped are rescued as quickly and as safely as possible."
Welsh Secretary Cheryl Gillan commented: "I am receiving regular updates from the Police Services and I will be praying for the safe rescue of all involved."
Expressing his deep concern, Neath MP Peter Hain said: "This is one of a number of small mines in the area. Obviously the families will be deeply worried."
Meanwhile, Neath AM Gwenda Thomas said the point of the contact for the area is Rhos Community Centre where those affected can talk to police and specialists.
Although most mines in south Wales are now closed, there are pockets of small-scale collieries still in operation.
Gleision Colliery, in operation since 1993, works coal under a very steep hillside above the banks of the river Tawe.