Hundreds of people imprisoned for demonstrating against last month’s coup in Myanmar were released Wednesday, a rare conciliatory gesture by the military that appeared aimed at placating the protest movement.

Witnesses outside Insein Prison in Yangon saw busloads of mostly young people, looking happy with some flashing the three-finger gesture of defiance adopted by protesters. State-run TV said a total of 628 were freed.

Also Wednesday, Thein Zaw, a journalist for The Associated Press who was arrested last month while covering an anti-coup protest, was released.

Myanmar’s security forces have cracked down violently on protests against a Feb. 1 coup that reversed a decade of progress toward democracy in the Southeast Asian country and ousted the elected government of Aung San Suu Kyi. The independent Assistance Association for Political Prisoners says that at least 275 people have been killed in connection with the crackdown. Thousands have also been arrested, and more than 2,000 remain in custody or have charges against them outstanding.

Wednesday’s release was an unusual overture by the military, which has so far seemed impervious both internal pressure from protests and outside pressure from sanctions. In the face of an increasingly brutal crackdown, demonstrators tried a new tactic Wednesday that they dubbed a silence strike, calling on people to stay home and businesses to close for the day.

The prisoners released appear to be the hundreds of students detained in early March. One lawyer, speaking on condition of anonymity because she fears drawing attention from the authorities, said all those released were arrested on March 3. She said only 55 people detained in connection with the protests remained in the prison, and it is likely they will all face charges under a law that carries a penalty of up to three years in prison.

The mass release came the same day that Thein Zaw was also freed. Thein Zaw told the AP that the judge in his case announced during a hearing that all charges against him were dropped because he was doing his job at the time of his arrest.

“I’m looking forward to meeting my family members,” he said. “I’m sorry for some colleagues who are still in prison.”

Meanwhile, messages online urged people to stay home Wednesday in protest — rather than flooding the streets as they have in the past — saying silence is “the loudest scream.” The messages explained the strike’s purpose was to honor the movement’s fallen heroes, to allow protesters to recharge and to contradict the junta’s claims that “everything is back to normal.”