BANGKOK (AP) — A powerful ethnic minority armed group battling Myanmar’s army in the country’s west claimed Monday to have taken hundreds of government soldiers prisoner when it captured a major command post.

The Arakan Army, the well-trained and well-armed military wing of the Rakhine ethnic minority movement, has been on the offensive against army outposts in the western state of Rakhine — its home ground — for about six months.

The group said in a video statement posted on the Telegram messaging app that soldiers belonging to the military government’s Operational Command No. 15 headquarters in Rakhine’s Buthidaung township surrendered after a siege.

Buthidaung is about 385 kilometers (240 miles) southwest of Mandalay, Myanmar’s second-largest city.

The reported capture of the base could not be independently confirmed. Myanmar’s military government made no immediate comment, and the spokesperson of the Arakan Army did not respond to questions sent by The Associated Press.