Berlin - A police helicopter became a common sight in the city's icy-blue winter skies this weekend as officers worked to keep people from storming onto frozen yet dangerous bodies of water. 

"It looked dramatic," says Ferdinand Pohl, who was on Weißer See with his daughter when a helicopter descended to warn the estimated 150 people pedestrians who had wandered onto the ice. "The helicopter was flying nose first and with the tail up like in the movies. It was only a few feet above the ice."

"Please get off the ice," officers said over the aircraft's speaker – the Polizei published a video of the event on Twitter. 

Photo: Berliner Zeitung/Markus Wächter
Sunday afternoon at Urbanhafen the ice went from strolling path to dancefloor. 

The helicopter made so much noise and whirled up so much snow that people were driven away by the artifical blizzard.

"The helicopter didn't take off again until everyone was off the ice," says the father. But it did little good – the ice quickly filled up once the police were gone but most children were so intimidated that they didn't want to go back out.

The helicopter also chased away people on Müggelsee, Lietzensee and at the Rummelsburger Bucht.

"We are currently active with all kinds of vehicles – on land, on water and in the air," a police spokesperson said Sunday. Neither the police department nor the fire department had ruled the ice safe to walk on.  It was far too dangerous, she said.

And the officials' concerns were confirmed: According to the fire brigade, a father with a stroller broke through the ice on Schlachtensee with his one-year-old son. Both were transported by helicopter to a hospital. And they weren't the only ones that ended up in the water at Schlachtensee.

Police and the fire department as well as Germany's lifeguard society warn against stepping on the ice. Despite the dangers, police often don't send patrol cars to warn foolhardy pedestrians – the loudspeaker can't be heard on the lake.

"That's why the helicopter flies out and targets the people on the ice specifically," the spokesperson said.

Photo: Berliner Zeitung/Markus Wächter
The canal in front of Urban hospital tranformed into a winter wonderland.

At Rummelsburger Bucht, snow was cleared to create a hockey rink and a man was seen riding his bike from one shore to the other. In the distance, even a moped rider was spotted on the ice. People sipped from thermoses. Everything was chill.

At Urbanhafen, the police cordoned off the shore with red and white tape. But it was little use as locals had been using the frozen water as a skating rink for three days. A resident said the police would occasionally stop by to ask people to get off the ice.

"Sometimes there's just a patrol car on the shore as a deterrent," the woman said. "But as soon as the police leave, the ice is full again."

Photo: imago/Sabine Gudath
Seen as a recommendation, not an order.

By late Sunday afternoon, the ice rink had transformed into a party zone. People danced in a large circle, the first public party in weeks. 

Safe surfaces on Berlin lakes and canals are rare. One woman remembered February of 1987 when it was -20 for weeks, allowing authorities to offically open the surfaces for the public.

"We walked from one shore to the other at Müggelsee," she said.

The real trouble will begin Tuesday when the extreme cold ends and temps are expected to head above freezing quickly, setting in a thaw on the water.