The Arakan Army (AA) claims to have seized a large Myanmar junta base at Traunaing in Paletwa Township, Chin State, after 21 days of attacks.
The AA is also attempting to seize the major Hnonebuu base in the township since November 14.
The armed group, which is based in neighboring Rakhine State, said it faced repeated junta airstrikes and shelling and accused the regime of using chemical weapons. Airstrikes continue in defense of the Hnonebuu base.
Many weapons and ammunition were seized and numerous dead junta troops were found at the base, said the AA.
It added that its forces suffered casualties but did not give details. The Irrawaddy could not independently verify the reports.
AA spokesman Khine Thu Kha recently told The Irrawaddy that the two outposts were used to oppress Chin and Rakhine communities in Paletwa Township.
As part of Operation 1027, the AA attacked military targets across northern Rakhine State and Paletwa on November 13, ending a yearlong ceasefire agreed with the regime.
The group says it seized around five bases and occupied another 40 positions abandoned by regime troops.
Clashes continue in Pauktaw, near the Rakhine State capital Sittwe, as AA troops attempt to seize the town.