Seven tower blocks in Wales tested after Grenfell fire
Samples of the same type of cladding used on Grenfell Tower is being tested from seven social housing tower blocks in Wales, the BBC understands.
The Welsh Government has urged social landlords to test if they have aluminium composite material (ACM), which has come under scrutiny since the fire at the London high rise.
Swansea Council is having cladding from four high-rise blocks examined.
The three other blocks and their owners have not been identified.
Ministers have asked social landlords to have the cladding tested at the same centre which is conducting testing in England.
The test - devised in response to the disaster - checks the combustibility of the filler material in between aluminium panels that make up the cladding.
Results from the tests, which are to be paid for by the Welsh Government, are expected within days.
ACM-type cladding was used at Grenfell Tower. However the specific brand - Reynobond PE - is not in use in Wales' social housing stock.
Swansea council is testing four of its 11 high-rise blocks which have ACM - three blocks at Clyne Court in Sketty and one block at Jeffreys Court in Penlan.
Cladding on more than 100 high-rise buildings in England have failed the tests.
Swansea council leader Rob Stewart has expressed fears the tests could fail if they go beyond building regulations.
But the council said it was confident its buildings were safe and insisted that materials used either met or exceeded the current rules.
The authority said the cladding sent for testing had a mineral core rather than a plastic core, and that fire breaks had also been fitted.
Mr Stewart said: "Whilst we know the materials used in our blocks either meet or exceed current building regulations, we have not been told what testing will be carried out.
"If the testing goes beyond those building regulations requirements then we are likely to fail those tests.
"This appears to be what is happening in England where all blocks have failed the tests to date, although we have not been given details of what was tested and which elements have failed.
"I've asked the Welsh Government to clarify what tests will be carried out so that everyone, particularly tenants, are aware of the facts."
To reassure tenants, the council is providing officers on site "at all hours of the day" until the results of cladding tests are known.
It also said it is to install sprinklers in its 11 blocks - at a cost of £1m - and has also committed to remove and replace materials that fail the tests.
It earlier emerged that a number of other organisations are testing cladding in tower blocks that have not used aluminium composite materials. It is understood that they are not using the same test, and it is thought the measure in these cases is being done to reassure tenants.
A Welsh Government spokesman said: "We can confirm that there are seven tower blocks in Wales where ACM cladding is, or is suspected to be, present, and are consequently being tested."