Saturday is the first day of the traditional New Year in Myanmar and the last day of a five-day holiday usually celebrated with visits to Buddhist temples and rowdy water throwing and partying in the streets.
Suu Kyi is among 3,141 people arrested in connection with the coup, according to a tally by the Assistance Association for Political Prisoners (AAPP) activist group.
“These detainees are mostly from before February 1 but there are also some who were imprisoned after,” Prisons Department spokesman Kyaw Tun Oo told Reuters by telephone.
Asked if any of those being freed might have been detained in connection with the protests against military rule, he said he did not have details of the amnesties.
While the military was freeing the thousands of prisoners, it was also seeking 832 people on warrants in connection with the protests, the AAPP said.
Among them are 200 people — including several internet celebrities, actors and singers who have spoken out against the coup — wanted on a charge of encouraging dissent in the armed forces.
Two of them, the married couple of film director Christina Kyi and actor Zenn Kyi, were detained at the airport in the main city of Yangon on Saturday as they tried to leave the country, several media outlets reported.
A spokesman for the junta did not answer calls seeking comment.
The ousted government had held power for the first five years of civilian rule since nearly half a century of army rule ended.
People infuriated by the return of military rule have taken to the streets day after day to demand the restoration of democracy, defying crackdowns by the security forces in which 728 people have been killed, according to the AAPP’s latest figures.
Political leaders, including ousted members of parliament, announced the formation of a National Unity Government (NUG) on Friday including Suu Kyi and leaders of the anti-coup protests and ethnic minorities.
The NUG says it is the legitimate political authority and has called for international recognition.
The junta has yet to comment on the unity government but has said it will hold a new election within two years and hand power to the winner.
The hugely popular Suu Kyi faces various changes, including violating an official secrets act that could see her jailed for 14 years. Her lawyers dismiss the charges.
Her supporters suspect the military will use the charges to exclude Suu Kyi and perhaps her political party from any future election.