The United States on Monday condemned Myanmar’s execution of political activists and elected officials and called on the military government to immediately end the violence.

“The United States condemns in the strongest terms the Burmese military regime’s heinous execution of pro-democracy activists and elected leaders,” the National Security Council said in a statement. Myanmar is also known as Burma.

The U.S. called on Myanmar’s rulers to “release those they have unjustly detained and allow for a peaceful return to democracy in accordance with the wishes of the people of Burma.”

Myanmar state media said the Southeast Asian country executed four democracy activists it had accused of helping carry out “terror acts” against the government that seized power last year in a coup. The four had been sentenced to death in January in a closed-door trial.

Those executed were democracy figure Kyaw Min Yu, better known as Jimmy; former lawmaker and hip-hop artist Phyo Zeya Thaw, an ally of ousted Myanmar leader Aung San Suu Kyi; and two others, Hla Myo Aung and Aung Thura Zaw.

The U.S. was among numerous critics of the executions.

Myanmar’s National Unity Government, a shadow administration outlawed by the ruling military junta, said it was “extremely saddened. … The global community must punish their cruelty.”

Japanese Foreign Minister Yoshima Hayashi said, “This goes against our repeated calls for all detainees to be freed. It also will sharpen the feelings of the [Myanmar] people and worsen the conflict, as well as deepening Myanmar’s isolation from the international community. It is a matter of deep concern.”

Richard Horsey, a senior adviser on Myanmar at the International Crisis Group, said, “Any possibility of dialogue to end the crisis created by the coup has now been removed. This is the regime demonstrating that it will do what it wants and listen to no one. It sees this as a demonstration of strength, but it may be a serious miscalculation.”

Amnesty International regional director Erwin van der Borght said the “executions amount to arbitrary deprivation of lives and are another example of Myanmar’s atrocious human rights record. … The international community must act immediately, as more than 100 people are believed to be on death row after being convicted in similar proceedings.”

Some material in this report came from Reuters.