Myanmar Military Seizes Power in Coup

Tensions have been rising for days over the results of a November election that Ms. Suu Kyi’s party won by a landslide. Only the second truly contested and democratic vote since the end of military rule in the Southeast Asian country, it was called fraudulent by the army-backed opposition party, which alleged false names on voter lists. Myanmar’s Union Election Commission has denied that claim.

The announcement on military television said the commission hadn’t adequately addressed the allegations, making a one-year state of emergency necessary to restore order and stability. Power has been transferred to army chief Min Aung Hlaing, it said. Parliament was scheduled to convene on Monday for its first session since the election.

“The United States is alarmed by reports that the Burmese military has taken steps to undermine the country’s democratic transition,” White House spokeswoman Jen Psaki said about the developments in Myanmar, also known as Burma. “The United States opposes any attempt to alter the outcome of recent elections or impede Myanmar’s democratic transition, and will take action against those responsible if these steps are not reversed.”

President Biden had been briefed on the situation, the spokeswoman said. Myanmar’s military couldn’t be reached for comment.

Myo Nyunt, a spokesman for Ms. Suu Kyi’s party, the National League for Democracy, said Ms. Suu Kyi, President Win Myint and other senior party officials were detained by the military shortly after 4 a.m. local time Monday.

Ms. Suu Kyi, the daughter of a Myanmar independence hero, spent years under house arrest during military rule, winning a Nobel Peace Prize for her struggle for democracy. After the military loosened its grip on power, the U.S. and other foreign governments began lifting longstanding sanctions against the country. Ms. Suu Kyi’s party came to power in the 2015 vote that marked a historic shift. Her official title is state counselor, but she effectively served as leader of the Southeast Asian nation.

Still, the military has remained powerful. The constitution grants it control of the defense and interior ministries. Soldiers are also guaranteed a quarter of the seats in the parliament, enough to veto constitutional changes. Ms. Suu Kyi’s advisers have long said she walks a tightrope and must be careful not to give the generals an opening to retake full power.

Myanmar and Ms. Suu Kyi’s administration were rocked by major challenges in her first term. The leader, once celebrated as a human-rights icon, faced widespread international criticism for her handling of genocide allegations against Myanmar after a brutal military operation in 2017 forced 700,000 members of the Rohingya Muslim minority out of the country. Ms. Suu Kyi has echoed the military’s arguments that the action was a legitimate security operation.

Monday’s events throw into political turmoil a country whose move away from military rule, though slow and rocky, was seen as a win for democracy. Telephone and internet lines were down in large parts of the country.

Historian Thant Myint-U, whose books on Myanmar include “The Hidden History of Burma,” said the country is “at a precipice.”

“It’s a country with dozens of warring armies, hundreds of militia, a $70 billion illicit-drug industry, tens of millions that have fallen into poverty because of the economic downturn this past year, and now a collapse of whatever understanding there had been between the army and the National League for Democracy, the two most important political forces in Myanmar,” he said. “I think the outside world often failed to see how fragile Myanmar’s democracy transition was.”

Advocacy group Human Rights Watch called on Myanmar’s military to release Ms. Suu Kyi and others it said had been unlawfully detained. “The military’s actions show utter disdain for the democratic elections held in November and the right of Myanmar’s people to choose their own government,” it said.

Write to Niharika Mandhana at niharika.mandhana@wsj.com, Feliz Solomon at feliz.solomon@wsj.com and Sabrina Siddiqui at Sabrina.Siddiqui@wsj.com