YANGON, March 27 (Xinhua) -- Myanmar military columns have been attacked by the Arakan Army (AA), an ethnic insurgent group, in western Rakhine state, leaving casualties from both sides, the Office of the Commander-in-Chief of the Defense Services said on Wednesday.

In two incidents on Sunday and Monday, the military columns, conducting security operation near Yaysoe Chaung and Kyiyapin villages in Yathedaung and Kyauktaw towns, were attacked by dozens of AA members with small and heavy weapons.

In Sunday's clash, when the military column reached the eastern bank of Nga San Baw creek, southwest of Yaysoe Chaung village in Yathedaung township, 10 AA members opened fire from inside a mangrove forest on the opposite bank. After 10 minutes' engagement, the AA group withdrew to the west.

On Monday, a military detachment conducting road security work near Kyiyapin village in Kyauktaw came under attack by 150 AA members.

Weapons and related materials were seized by the army.

The AA group has been blamed for escalating its attack on the government forces since the beginning of this month.