The military is also pardoning 3,000 prisoners to mark this year's traditional New Year holiday.
Myanmar's jailed former leader and Nobel laureate Aung San Suu Kyi has been moved from prison to house arrest as a health measure amid a severe heat wave, the military said.
Major General Zaw Min Tun told foreign media on Tuesday that Aung San Suu Kyi and the president of her ousted government, Win Myint, were among elderly and sick prisoners transferred from prison.
“Since the weather is extremely hot, it is not just for Aung San Suu Kyi… For all those who need the necessary precautions, especially elderly prisoners, we are working to protect them from heat stroke,” he said.
Aung San Suu Kyi, 78, has been imprisoned by Myanmar's military since it overthrew her government in a coup in 2021.
He has been serving a 27-year prison sentence in Naypyidaw for a variety of criminal convictions that his supporters and human rights groups say were fabricated for political reasons. Win Myint was serving an eight-year prison sentence in Taungoo, in the Bago region of Myanmar.
Myanmar's meteorological department said Naypyidaw recorded temperatures of 39 degrees Celsius (102.2 degrees Fahrenheit) on Tuesday.
Zaw Min Tun did not say where the freed prisoners would be taken. Before being sent to prison, Aung San Suu Kyi was reportedly held in a safe house inside a military base.
In February, Aung San Suu Kyi's son, Kim Aris, said she was being held in solitary confinement and was in good spirits “although her health is not as good as in the past.”
Aris had previously said that reports that his mother had been moved to house arrest in July last year were not true. At the time, he called the reports “disinformation” spread by the military to appease the international community.
Many governments around the world have called for the unconditional release of Aung San Suu Kyi and thousands of other political prisoners and some, including the United States, the European Union and the United Kingdom, have imposed sanctions against the Southeast Asian country's military.
Three years after the coup, Myanmar's military faces its biggest challenge to its rule as an armed resistance movement, allied with the National Unity Government (NUG) created by politicians allied to Aung San Suu Kyi, gains momentum in several fronts.
A NUG spokesperson on Tuesday called for the unconditional release of Aung San Suu Kyi and Win Myint.
“Moving them from prisons to houses is good as houses are better than prisons,” spokesman Kyaw Zaw told Reuters news agency on Tuesday night.
“However, they must be released unconditionally. “They must take full responsibility for the health and safety of Aung San Suu Kyi and U Win Myint.”
News of Aung San Suu Kyi's transfer came as the military also granted amnesty to more than 3,000 prisoners ahead of this week's traditional Thingyan New Year holiday.
It was not immediately clear whether those released would include pro-democracy activists and political prisoners who were arrested for protesting against army rule.
State broadcaster MRTV said the head of the ruling military council, General Min Aung Hlaing, had pardoned 3,303 prisoners, including 28 foreigners who will be deported from Myanmar. He also reduced sentences for others.
Mass amnesties during the holiday are not unusual in Myanmar.
The Assistance Association for Political Prisoners (AAPP), which has been monitoring the post-coup crackdown, said in its most recent update on April 12 that some 20,351 people were detained for opposing the military.
