GENEVA: Official tolls showing the number of deaths directly or indirectly attributed to the COVID-19 pandemic are likely to be a "significant undercount", the World Health Organization said on Friday, saying 6-8 million people may have died so far.

Presenting its annual World Health Statistics report, the WHO estimated that total deaths from the COVID-19 pandemic in 2020 were at least 3 million last year or 1.2 million more than officially reported.

"We are likely facing a significant undercount of total deaths directly and indirectly attributed to COVID-19," it said.

The UN agency officially estimates that around 3.4 million people have died directly as a result of the COVID-19 pandemic by May 2021.

"...This number would truly be two to three times higher. So I think safely about 6 to 8 million deaths could be an estimate on a cautionary note," said Samira Asma, WHO's Assistant Director-General in its data and analytics division at a virtual press briefing.

WHO data analyst William Msemburi said that this estimate included both unreported COVID-19 deaths as well as indirect deaths due to the lack of hospital capacity and restrictions on movements among other factors.

"The challenge is that the reported COVID-19 [death toll figures] is an undercount of that full impact," Msemburi said.

The WHO did not give a breakdown of the figure, referred to by health experts as ""excess mortality".