The cause of a fire at a block of flats in Gwynedd looks set to remain a mystery.

Four people had to be rescued from Plas Twthill in Caernarfon on Tuesday night after a blaze broke out at the front of the building.

Residents have been left unable to return to their homes for now and have been temporarily rehoused as North Wales Housing assess the damage.

The fire service and police launched an investigation into what caused the blaze.

But today, the fire service said it will never be known what started the fire as investigators were unable to determine the cause.

Police and the fire service are investigating a blaze in Caernarfon
Police and the fire service are investigating a blaze in Caernarfon

Flames ripped through the entryway to the block of flats, leaving four residents unable to get out.

They were rescued from the flats by fire crews, but none of them were injured.

Neighbour David Davies told how huge flames engulfed the doorway to the flats.

He said: "I was just about to go to bed when I saw a huge wall of flames and lots of people running around.

"My neighbour called the fire service and they were here within three or four minutes. They were fantastic.

Neighbour David Davies lives opposite and saw the flames
Neighbour David Davies lives opposite and saw the flames

"The flames were very high and fierce and were climbing up the roof. It was terrible. People couldn't come out the front door, but some managed to come out the back. A few of the residents went into my neighbour's home.

"The firefighters did a fantastic job - they got it out within about half an hour and it was all over by about 12.10am. They were really brilliant."

North Wales Housing, who own the building, said they would continue to support any affected residents.

Fire damaged flats in Plas Twthill, Caernarfon
Fire damaged flats in Plas Twthill, Caernarfon

Brett Sadler, operations director at North Wales Housing, said: "We are pleased that no residents were injured in the fire at Plas Twthill, Caernarfon on Tuesday January 14.

"North Wales Housing are supporting and re-housing residents until we assess and rectify the damage to the property.

"North Wales Fire Service are still looking into the reason behind the fire. We are liaising closely with them and assisting with their enquiries.

"Thank you to North Wales Fire Service and North Wales Police for their quick response and hard work."