YANGON, Myanmar--Protesters gathered in Myanmar’s biggest city on Monday despite the ruling junta’s threat to use lethal force against people who join a general strike against the military’s takeover three weeks ago.

More than 1,000 protesters gathered near the U.S. Embassy in Yangon despite barriers blocking the way but left to avoid a confrontation after 20 military trucks with riot police arrived nearby. Protests continued in other parts of the city, including next to Sule Pagoda, a traditional gathering point.

Factories, workplaces and shops were shuttered across the country Monday in response to the call for a nationwide strike. The closings extended to the capital, Naypyitaw.

The junta had warned against a general strike in a public announcement Sunday night on state television broadcaster MRTV.

“It is found that the protesters have raised their incitement towards riot and anarchy mob on the day of 22 February. Protesters are now inciting the people, especially emotional teenagers and youths, to a confrontation path where they will suffer the loss of life,” the onscreen text said in English, replicating the spoken announcement in Burmese.

The junta’s statement also blamed criminals for past protest violence, with the result that “the security force members had to fire back.” Three protesters have been fatally shot.

Trucks cruised the streets of Yangon on Sunday night, blaring similar warnings.

The protest movement, which seeks to restore power to the elected government of Aung San Suu Kyi and have her and other leaders released from detention, has embraced nonviolence.

The nationwide strike was dubbed Five-Twos, for the five number twos in the numeric form of Monday’s date.

“I am joining the 22222 nationwide protest as a citizen of the country. We must join the protest this time without fail,” said 42-year-old Zayar, who owns a bottled water business in the capital. “So I’ve closed down my factory and joined the demonstration.”

Zin Mi Mi Aung, a 27-year-old saleswoman, also joined the strike.

“We don’t want to be governed by the regime," she said as people marched and chanted behind her. "We will fight against them until we win.”

Thousands of people gathered in the capital’s wide boulevards, many on motorbikes to allow swift movement in the event of any police action.

Reports and photos of protests in at least a dozen cities and towns were posted on social media. Overhead views, some shot from drones, showed massive crowds in six cities appearing to number in the tens of thousands.

There were pictures of a particularly colorful event in Taunggyi, the capital of Shan state, where scores of small red hot-air balloons were set aloft. A bigger one was adorned with a drawing of the three-finger salute adopted by the anti-coup movement. The city is famous for its annual hot-air balloon festival.

In Pyinmana, a satellite town of Naypyitaw, police chased people through the streets to arrest them. Reports on social media, including from worried family members, said police had arrested 200 people or more, mostly young people, and sent them to a military base. If confirmed, it would be the biggest mass arrest since the protests started.

The general strike was an extension of actions called by the Civil Disobedience Movement, a loosely organized group that has been encouraging civil servants and workers at state enterprises to walk off their jobs. Many transport workers and white-collar workers have responded to the appeal.

On Saturday, a General Strike Committee was formed by more than two dozen groups to provide a more formal structure for the resistance movement and launch a “spring revolution.”

The United States and several Western governments have called for the junta to refrain from violence, release detainees and restore Myanmar’s elected government. On Monday, the U.S. said it was imposing sanctions against more junta members because of killings of peaceful protesters by security forces.

Lt. Gen. Moe Myint Tun and Gen. Maung Maung Kyaw add to other military leaders and entities facing U.S. sanctions, and Britain and Canada have taken similar action since the military takeover.

The U.S. condemned the attacks on protesters, U.S. Secretary of State Antony Blinken said in a statement vowing to take further action if more violence occurred. “We call on the military and police to cease all attacks on peaceful protesters, immediately release all those unjustly detained, stop attacks on and intimidation of journalists and activists, and restore the democratically elected government,” he said.

Myanmar has been ruled by the military for most of its history since gaining independence from Britain in 1948. A gradual move toward democracy in the past decade allowed Suu Kyi to lead a civilian government beginning in 2016, though the generals retained substantial power under a military-drafted constitution.

Her party won last November’s election by a landslide, but the military stepped in before Parliament was to convene on Feb. 1, detained Suu Kyi and other government officials and instituted a one-year state of emergency. It contends the vote was tainted by fraud and plans to reinvestigate those allegations before a new election is held.