Despite the mild winter a surprisingly high number of elderly people died in the December to March period, the national statistics office CBS said on Monday.

The death rate reached its highest level in 20 years and a long-lasting flu epidemic is likely to be the cause, the CBS said.

The number of people in their 80s who died rose 15% to almost 24,000. The increase in the death rate among people in their 90s was higher – 27% – compared with the previous winter.

Cold winters are usually a cause of an increase in deaths among the elderly, the CBS said.

There was no increase in the death rate among people in their 60s and 70s because they would ‘seem to be more able to cope with flu’, researcher Jan Latten told news agency ANP.