BANGKOK (AP) — An alliance of ethnic rebel groups on Friday launched a coordinated offensive in northeastern Myanmar to seize military targets in areas near the Chinese border, the groups and residents of the area said.

The Arakan Army, the Myanmar National Democratic Alliance Army and the Ta’ang National Liberation Army, calling themselves the Three Brotherhood Alliance, said in a joint statement that they have begun “Operation 1027” in Myanmar’s Shan state. The offensive could become a new major front in the strife-torn Southeast Asian nation.

Major coordinated attacks initiated by opponents of Myanmar’s military government are relatively rare, partly because the army has a great advantage in weaponry and trained manpower.

“Our primary objectives in launching this operation are multi-faceted and driven by the collective desire to safeguard the lives of civilians, assert our right to self-defense, maintain control over our territory and respond resolutely to ongoing artillery attacks and air strikes” perpetrated by the military government, said the statement.

Maj. Gen. Zaw Min Tun, the spokesperson for the military government, acknowledged in a phone interview with pro-military media outlet NP News that towns in northern Shan state had been attacked, and members of the security forces were killed in the town of Chinshwehaw, but did not give a number. Chinshwehaw is a small town that borders China, about 320 kilometers (200 miles) northeast of Mandalay, Myanmar’s second largest city.

The groups in the rebel alliance, like other minority groups living in border regions, have struggled for decades for greater autonomy from Myanmar’s central government.

Fighting between the army and many ethic minority armed groups, including the alliance members, intensified after the military seized power from the elected government of Aung San Suu Kyi in February 2021.

Several groups, including those in the Three Brotherhood Alliance, have collaborated with pro-democracy militias formed after the military takeover. These militias, collectively known as the People’s Defense Force, now battle the army over much of the country.

The alliance’s statement said its members are also “dedicated to eradicating the oppressive military dictatorship, a shared aspiration of the entire Myanmar population.”

The politics of ethnic groups in the north is complicated because the area borders China, which maintains good relations with Myanmar’s ruling generals. The groups in the alliance also have good relations with China and have vowed to protect foreign investments in their territories where Chinese-backed projects are located.

Another link is that the Myanmar National Democratic Alliance Army, or MNDAA, is the fighting arm of Myanmar’s Kokang minority, who are ethnic Chinese.

Details of Friday’s fighting are difficult to confirm, since the area is difficult to access.

Battles were reported in the townships of Kyaukme, Kutkai, Lashio, Laukkaing, Muse and Namhkan in northern Shan state, beginning with simultaneous attacks at dawn.

Media in Shan state reported the alliance forces had attacked military targets, checkpoints, toll gates and police stations, and that Chinshwehaw — which hosts one of Myanmar’s five official border trade crossings with China — was seized by the MNDAA. It said the military responded with aerial bombardments and shelling and that many hundreds of civilians are fleeing to safer areas.

Photos on social media showed bodies apparently of security force personnel killed in the fighting, captured soldiers and damaged toll gates.

SHAN News, a local online media outlet, reported four people, including three children, were killed and six others wounded by artillery strikes in Kutkai and Namhkan townships.

A Laukkaing township resident confirmed to The Associated Press that Chinshwehaw and border trade checkpoints were seized by MNDAA on Friday morning. He spoke on the condition of anonymity because he feared reprisals from the military and rebel groups.

A member of Laukkaing’s police force told the AP that at least 17 policemen including a lieutenant were killed and others were wounded after the MNDAA attacked patrol cars and checkpoints. He spoke on the condition of anonymity because he is not authorized to release information.

Military spokesperson Zaw Min Tun said a hotel in Chinshwehaw was attacked by the MNDAA and hotel staff and civilians seized and taken away.

A truck driver from Lashio, a key trading post, said the town’s gates were closed after the rebel groups attacked a toll gate just outside of town. Road traffic was also stopped, said the truck driver, who spoke on condition of anonymity because he fears punishment from the authorities.

MNDAA-backed online media posted a statement from the group saying it had captured some strategic locations and blocked roads in order to raid online fraud operations in Laukkaing.

The alliance statement had said it is committed “to combatting the widespread online gambling fraud that has plagued Myanmar particularly along the China-Myanmar border.” That refers to casinos and other properties where organized crime carries out online and phone scams employing thousands of people, many tricked into coming from China by fake job offers but who end up working in conditions of near slavery.

The crime rings are headed by ethnic Chinese, often in cooperation with local Myanmar warlords. In recent weeks the Chinese government has pushed a crackdown on these operations, and thousands of people involved have been repatriated to China.