A family of North American black bears have been spotted playing on a frozen lake at a UK safari park, as they embraced the cold weather.

Mother bear Phoenix, and her four yearlings, Harvard, Maple, Colorado and Aspen, took to the ice after a lake froze over in their enclosure at Woburn Safari Park, Bedfordshire.

They were seen rolling around, play fighting and losing their balance, which park keepers described as “a unique reaction to the ice”.

The bears used their paws and noses to scratch at the ice as they cautiously navigated the slippery surface.

Keepers said the young bears engaged in playful sparring and “took advantage of their opponents’ unsteady footing on the icy terrain”.

Parts of the UK faced sub-zero temperatures at the weekend, with the mercury hitting -18.9C on Saturday morning in Altnaharra, Scotland, making it the UK’s coldest January night in 15 years.

Woburn experienced lows of -4C on Friday night, well below the typical average for England of about 1.5 to 1.6C.

The keepers at Woburn Safari Park said the weather had “posed some challenging conditions” but added it was “nice to know that it hasn’t stopped the bears having fun”.

While the bears are in a controlled environment, Bedfordshire Fire and Rescue Service warned against residents walking on frozen bodies of water.

A spokesperson said: “With sub-zero temperatures many bodies of water will freeze over, these may look like fun places to play but stepping onto the ice could cost you your life.”

They continued: “Avoid walking or playing near the edge. If you’re walking a dog, keep it on a lead so that they’re not at risk of falling in. If someone falls through the ice call 999 immediately, and never walk onto the ice to help them.”