The roof has now been cut up and taken away

The Kruger Tissues factory was evacuated after a 30x20m section of roof came off and landed on cars parked outside just after 1530 BST.

No-one was injured and the debris has now been taken away.

Meanwhile, the weather has also caused localised flooding in the Llanrwst area, where police have described Thursday's weather as "horrendous".

And nearly 3,000 homes lost power in the Benllech area of Anglesey, after lightning hit a substation, according to Scottish Power.

North Wales Fire Service said a saw and a crane were used to remove the debris from roof at the factory car park in Penygroes.

Llanrwst was hit by flooding earlier this year

"The people in the factory are all accounted for," said Watch Manager Alun Huws.

He said that, when the fire service had first arrived, the scene had been one of "devastation".

"About 15 vehicles were covered by the wreckage," he said.

Mr Huws added that the crews of the three appliances which attended the scene initially had to assume there could have been people trapped under the wreckage.

He added that winds in excess of 60mph had hampered the clear-up operation.

Around 120 people work at Kruger Tissues, which operates around the clock.

Most of the workers on the day shift were sent home, and staff on the evening and overnight shifts were told not to come in.

Flooding

North Wales Police have said that the flash floods in the Llanrwst area have been caused by a "horrendous" storm on Thursday afternoon.

No roads are closed, but there is severe surface water in the area. The rivers have not burst their banks.

On Thursday evening, a spokesman for Conwy Council said the highways department had taken more than 20 calls about possible flooding in the Llanrwst and Pandy Tudur areas.

And BBC Wales weather forecaster Derek Brockway warned that more bad weather was on the way.

"There is more wind and heavy rain on the way on Friday, particularly in the west and over the mountains," he said.

"There is a risk of localised flooding."