UK floods warning York
The River Ouse flows through York after heavy overnight flooding on December 27, 2015 in York, EnglandIan Forsyth/Getty Images

Hundreds of people have been evacuated from their homes in York as "unprecedented" levels of flooding presented a significant danger to life in the city. Up to 3,500 properties – including historic buildings in the centre – are now at risk of flooding after the city's two rivers burst their banks.

The River Ouse is more than four metres higher than its normal level but will not peak until tomorrow afternoon (28 December). The River Foss is hitting record heights in urban areas. The worry is that, even though the rain has subsided, water coming from the nearby saturated dales will flow into the river and could bring further flooding to York.

Thousands have taken to Twitter to share photographs of the damage so far. Many used the hashtag #Yorkfloods to share their images.

UK floods warning York
The River Ouse flows through York as water levels increase on December 27, 2015 in York, EnglandIan Forsyth/Getty Images

David Rhodes, who runs a taxi firm in York, told Sky News: "This time we've actually got flood defences in but they haven't worked. It's 15 years since it's been this high. We get it in every year but only up to the door and then it recedes. But this time, I don't know, it's happened so quick."

The Environment Agency told The Independent that water pouring into the Foss Barrier building put it in danger of collapsing, meaning that the gate holding back water from the city centre had to be opened in case it became locked in place. The removal of the defences put even more areas at risk and extended the evacuation zone.

"The immediate area at risk is the city centre and areas of Huntington, Tang Hall, Osbaldwick and Foss Islands," the spokeswoman told the newspaper. "People in these areas should start to move valuables to upper floors and be prepared to be evacuated," she added.

UK Severe Flood Warning
Members of Cleveland Mountain Rescue and soldiers from 2 Battalion The Duke of Lancasters Regiment assist members of the public as they are evacuated from the Queens Hotel in York city centre as the River Ouse floods on December 27, 2015 in York, EnglandIan Forsyth/Getty Images

The evacuations have seen an additional 500 members of the armed forces sent to northern England. The dispatch brings the number of soldiers working on the disaster to 900, with 1,500 more on standby.

There are currently more than 20 "severe" flood warnings throughout England, Wales and Scotland. A "severe" warning means the floods present a genuine danger to human life in the area.

The majority of the soldiers sent to help have been deployed in Cumbria, Yorkshire and Lancashire where scores of families have had their Christmases ruined by torrential rain and flooding. Rivers burst their banks, sending water gushing into areas not used to flooding and lacking any form of flood defences.

UK Severe Flood Warning
A man paddles his kayak along a flooded street on December 27, 2015 in York, EnglandIan Forsyth/Getty Images

The worst of the flooding has been around Leeds and Greater Manchester, where major roads have been closed and up to 7,000 left without power, according to BBC News. Electricity North West warned power may not be restored until tomorrow evening, and urged people in Rochdale to turn off their Christmas lights to help save electricity.

Elsewhere, the Foss Barrier water pumps – which control the flow where the River Foss joins the River Ouse – were overwhelmed and had to be lifted, putting additional areas of York at serious risk. Residents of the Windsor House residential home in the city have already had to be evacuated after the basement flooded and waters continued to rise.

The next 24 hours presents a worrying time for many families in northern England, with the flood risks not expected to peak until tomorrow afternoon. Already rivers such as the Aire in Leeds have reached "record levels" meaning the flood threat in the city is unprecedented.

UK floods: Aerial footage shows large swathes of Yorkshire underwaterIBTimes UK

David Cameron this morning chaired an emergency conference call with members of the government's Cobra committee in relation to the floods. Speaking after the call, the Prime Minister said "level of the rivers plus the level of rainfall has created an unprecedented effect, and so some very serious flooding. We will do everything we can to help people in this, their hour of need." Mr Cameron is expected to visit some of the flood-hit areas in northern England tomorrow.