BANGKOK--Guerrillas from the Karen ethnic minority on Thursday claimed to have captured the last of the army’s outposts in Myawaddy township in eastern Myanmar, virtually clearing the way for them to take over the town of Myawaddy, the major crossing point for trade with Thailand.

The Karen National Union, the ethnic group’s leading political body, said in a statement posted on Facebook that its armed wing, acting together with the affiliated Karen National Defense Organization and allied pro-democracy forces, had captured the garrison of the army’s Infantry Battalion 275, about 4 kilometers (3 miles) to the west of the town before dawn on Thursday, after besieging it since the start of the week.

The fall of Myawaddy would be another major setback in the army’s war against resistance forces since last October, when an alliance of three other ethnic rebel groups launched an offensive in the country’s northeast.

Over the past five months, the army has been routed in northern Shan state, where it surrendered control of several border crossings with China, and in Rakhine state in the west, and is facing active challenges elsewhere.

The nationwide conflict in Myanmar began after the army ousted the elected government of Aung San Suu Kyi in February 2021 and suppressed widespread nonviolent protests that sought a return to democratic rule.

Myawaddy, in Kayin state, is opposite the Thai district of Mae Sot in Tak province and is connected by two bridges across the Moei River It is Myanmar’s most active trading post with Thailand.

The fighting in Myawaddy has alarmed officials in Bangkok, who fear the prospect of large numbers of people fleeing across the border. Thai Foreign Minister Parnpree Bahiddha-Nukara said Tuesday that Thailand can accommodate about 100,000 people in safe areas on a temporary basis. Mae Sot district has in the past sheltered thousands of Myanmar villagers seeking safety.

With Infantry Battalion 275 garrison’s capture, all army outposts in the township have been seized and the resistance groups will pursue those soldiers who remain at large, said the statement from the KNU.

“We want to inform the public not to fear and to cooperate with us,” the statement said.

In a separate statement, the KNU said retreating soldiers seeking to cross into Thailand for refuge were hiding on the Myanmar side of the No.2 Myanmar-Thailand Friendship Bridge.

Photos carried by Thai media showed men they identified as Myanmar soldiers resting by the bridge.

The Karen are the third biggest ethnic group in Myanmar, making up about 7% of its 58 million population. Like other minority groups living in border regions, the Karen have sought greater autonomy from Myanmar’s central government for decades, with the KNU and its armed wing, the Karen National Liberation Army leading their struggle.

Although the Karen are among the most experienced of the armed ethnic groups, they lack the heavy weapons some other rebel organizations have, and also suffer from factionalism. The Karen make up a large part of about 90,000 refugees from Myanmar who live in nine long-term refugee camps in Thailand after fleeing previous rounds of fighting.

A Karen guerrilla involved in the resistance offensive told the Associated Press that their combined forces had seized the Infantry Battalion 275 garrison late Wednesday night.

The guerrilla, who spoke on condition of anonymity because he is not authorized to release information, said the resistance forces collected weapons from the garrison on Thursday. The KNU statement included photos of what it said were captured weapons.

A journalist covering the fighting in the area also confirmed the seizure of the garrison and weapons, saying the soldiers withdrew from the garrison overnight. He along with other individuals in Myawaddy willing to speak about the situation, spoke on condition of anonymity because of fear for their safety.

A resident of Myawaddy living near the garrison told the AP by phone that the retreat of the soldiers came after the Border Guard Force units negotiated between the army and the combined resistance force. He said a jet fighter dropped two bombs near the garrison at 10:30 a.m. on Thursday but no casualties were reported.

The Border Guard Force units in Kayin state are nominally affiliated with the military but announced last month they were cutting their ties and establishing themselves independently under the name of the Karen National Army.

A member of the Karen National Union/ Karen National Liberation Army-Peace Council, another Karen organization based in Myawaddy confirmed to the AP that the new Karen National Army was playing in a major role in negotiations between the resistance and the Myanmar military.

He said the Karen National Army units had pledged to Myawaddy’s residents that they would try to not let a single bullet hit the town, and were patrolling and taking other security measures,

Another Myawaddy resident also told the AP that while he was driving in the town he saw hundreds of people evidently seeking to cross into Mae Sot in Thailand at the bridge checkpoints.