WARSAW, Poland -- Statistics for 2020 show deaths spiked in Poland to a level unseen since World War II and births sharply declined, trends attributed to the COVID-19 pandemic and described by some as a demographic crisis.

The data reported Tuesday by the daily newspaper Dziennik Gazeta Prawna came from a state register that includes weekly births and deaths.

Poland, a nation with a population of more than 38 million, registered 357,400 births last year, the lowest number since 2005, and some 486,200 deaths from various causes, the highest number registered since the war. The overall data showed a population loss of some 129,000 people, compared to a decline of some 36,400 the year before.

Poland's population has slowly decreased in the past two decades mostly due to the emigration of young people seeking better opportunities.

The low birth rate surprised observers because some experts predicted the lockdown measures the Polish government has imposed on and off since mid-March would lead to a baby boom, the newspaper said. Communist-era martial law restrictions in Poland during the early 1980s produced such an uptick in births.

Demography expert Piotr Szukalski told Dziennik Gazeta Prawna he thinks that deep concerns about the spread of the coronavirus are to blame.

Minister of Family and Social Policy Marlena Malag ascribed the high death rate to the pandemic and said it would take a long time for the current government program of family benefits intended to boost the birthrate to reverse the negative trend.

Commenting on data the state agency Statistics Poland released in December for 11 months of 2020, economist Rafal Mundry said the number of deaths was the highest since World War II, and the number of births the lowest in 15 years.

"We have a huge demographic crisis," Mundry said on Twitter.

In 2019, some 30,000 people died in Poland each month on average. In November, when COVID-19 cases spiked, the country registered almost 60,400 deaths.

The high death rate continued in the first three weeks of 2021, with almost 29,000 deaths, compared to some 24,800 deaths in the first three weeks of 2020, before the pandemic.