Russian meteorologists have been trapped inside their remote arctic weather station for nearly two weeks, waiting for the bears to move on.
The mystery surrounding the death of Knut the polar bear, who collapsed in front of hundreds of shocked zoo visitors, has been solved.
New research suggests polar bears' genes may hold the answer to fighting heart problems linked with obesity in humans.
Scientists believe the bears' genetic make-up has adapted so that they can eat a diet containing very high levels of fat without any sign of heart disease.
Lead researcher Professor Rasmus Neilsen, of the University of California at Berkeley, said learning more about the bears' DNA may allow scientists "to modulate human physiology down the line".
Two 14-week old polar bear twins were presented to the public for the first time today.
The pair, who were seen exploring their enclosure at the Hellabrunn zoo in Munich, Germany, were born in December to mother Giovanna. They have yet to be named.
A pair of newborn polar bear cubs in Munich have been captured opening their eyes for the first time. The twins - Europe's first polar bear cubs in 2013 - were born at Hellabrunn Zoo on December 9.
Cameras installed in the maternity den showed them snuggling up to their mother, seven-year-old Giovanna, and opening their eyes for the first time.
The zoo said on Thursday that the twin cubs are making good progress and are now exploring their home - two litter boxes and a play area in the den - if not yet on foot, then at least with their eyes.
Read: Orphaned polar bear cub settles into his new home
A polar bear cub orphaned after his mother was killed by a hunter is being cared for by zoo staff in Alaska.