Myanmar’s Southeast Asian neighbors condemned the governing military’s murder of four political activists on Tuesday, calling it “very abhorrent” and damaging to regional attempts to de-escalate the conflict.

The 10-member Association of Southeast Asian Nations (ASEAN), which includes Myanmar, was “very worried and deeply dismayed” by the killings, as well as their timing, which came only a week before the bloc’s next conference.

The military, which took power in a coup last year, declared in state media on Monday that the activists had been murdered for helping “terror actions” by a civilian resistance organization, the first executions in decades in Myanmar.

The announcement sparked international anger, with the US, the UK, Australia, the European Union, and senior UN officials condemning the junta of cruelty.

A prisoner support group source informed Reuters that a demonstration had taken place within the facility. According to the news website Myanmar Now, some detainees were beaten by prison authorities, and roughly 15 of them were removed from the main population.

The junta has yet to reply to foreign criticism, although it has repeatedly accused the UN and western nations of interfering in its affairs. Its spokesman was scheduled to attend a normal press conference later that day.

Tom Andrews, the United Nations Special Rapporteur on Human Rights in Myanmar, expressed alarm over the increase in executions. In Myanmar, he added, at least 140 individuals had been condemned to death.