As night falls in the flood-ravaged villages of Yorkshire in northern England, a group of bikers dressed in black leather jackets and bandanas begin their patrol against looters.

Armed only with torchlights and donning reflective vests over their biker gear, around 30 hefty men and women in black walk streets strewn with household belongings as the region braces for more flooding on Wednesday.

"We came down to have a nose around and try and let people know there was a presence on the street," said Lloyd Spencer, chairman of the Drifters motorcycle club, who runs the Northern pub in nearby Bradford.

"The police are stretched dramatically at the moment, they can't do anything," the bearded 57-year-old, wearing a leather waistcoat with the name of his club and a patch reading "Biker Dad", told AFP.

Fellow club member Dave Cariss, who wore a black hoodie, said some local residents were sceptical when the bikers began their patrols on Sunday.

"At first they did look a bit intimidated by us but once we went around and told people who we are and why we're here they warmed to us pretty fast actually," he said.

- 'Big chaps' -

Thousands of people have been forced to evacuate their homes in northern England and as they return temporarily leave their belongings stacked up outside their homes to clean up, leaving them vulnerable to thieves.

"Last night we were chasing three or four people around. We managed to deter about five by the end of the night," said Kath Dearden, member of the Pyeratz motorcycle club -- one of several bikers from other groups who have joined the Drifters on patrol.

Dearden briefed around 30 bikers, including from the Broken Bones club, before starting a patrol into the early hours of Wednesday, telling them: "We're not here to detain people, we're here to deter people.

"We're here to stop people taking what they want because at the end of the day these people have lost everything," she told the bikers.

She later told AFP: "The local people are stunned, they keep bringing us food and drink, they are waving at us. They say they are safe in their beds now."

Spencer said he and Prentiss were first alerted to the problem through social media.

"We saw something on Facebook about looters," he said.

"We're big chaps, a lot of us. If people see us they're liable to go away," he said.

"We get negative press but we're normal blokes, most of us," said Spencer, adding that he and the others would not be on their beloved motorbikes because of the high water -- resorting to cars and vans instead.

- 'Not vigilantes' -

Spencer said the police had welcomed the bikers' help and locals had kept them warm with pots of tea and chip butties -- a type of sandwich made up of French fries in a buttered bread roll typical of northern England.

"There's loads of people out there but once you get to nighttime there's nobody," said Spencer.

One flood-hit town, Hebden Bridge, was "like a warzone" with no street lighting, he said.

"We've had a few vans pull up, take goods and we've had to pull up behind them. They then seem to think it's better to put it back," he explained.

"We haven't had to use any physical force. We're not vigilantes, we're not going to beat anybody up, it's just looking after other people."

The bikers also say they have scared off potential burglars at a school and Spencer said they would be holding a fundraising night at his pub on Saturday to buy new Christmas toys for local children.

Spencer said the floods have covered such a wide area that "even we were stretched" for night-time patrols.

Police said they had received some reports of people in vans "taking dry goods left outside flooded homes" and have stepped up their own patrols.

"It is extremely disappointing to see victims of the floods being targeted in this way," said Mark Grange from North Yorkshire Police.

"It is impossible to comprehend why anyone would want to bring further suffering to those who are already in a very vulnerable situation," he said.