YANGON, MYANMAR -- More than a quarter of Myanmar's prison population is to be released, the president's office announced Friday, as calls grow to ease pressure on overcrowded jails with coronavirus fears gripping the country.

The Southeast Asian nation grants an annual amnesty to thousands of prisoners to mark its April New Year holiday, but this is the largest ever recorded.

It comes as governments around the world -- including the US, parts of Europe, and Colombia -- grapple with overcrowded prisons as fears spiral of virus outbreaks behind bars.

So far Myanmar has officially confirmed 85 cases of COVID-19, including four deaths, but experts fear the real number is many times more due to the low numbers tested.

The country is under a nationwide lockdown and there has been growing pressure to release inmates from what Human Rights Watch (HRW) calls "horribly overcrowded and unsanitary" jails.

"To mark Myanmar New Year, by respecting humanitarian ground and peace in mind of the people, the president pardons altogether 24,896 prisoners from various prisons," a statement from the president's office said.

It added that 87 foreigners included in the amnesty would be deported.

The release would start immediately, a senior officer of the prison department in Myanmar's capital Naypyidaw told AFP without giving further details

"We're expecting the country's political prisoners to be included in the release," said Bo Kyi, co-founder of the Assistance Association for Political Prisoners (AAPP).

The organisation says there are currently 76 prisoners of conscience serving sentences behind bars.

A Rohingya activist, who asked not to be named, told AFP he had heard around 1,500 Rohingya Muslim prisoners would also be included on the list.

There are currently nearly 100,000 inmates across the country's prisons which have space for just 62,000, according to HRW.

Last year's amnesty included the high-profile cases of two Reuters journalists, Wa Lone and Kyaw Soe Oo, who spent more than 500 days behind bars over their reporting on the Rohingya crisis.