Myanmar Army fighter jets launched air strikes on a Karen village on 27 March, killing at least three and injuring eight.
Bombs were dropped on Day Pu No village in the Papun district of Karen state, an area with a large Christian population.
A second bombing raid on Sunday 28 March against villages and a displacement camp in the Mutraw district of Karen forced 3,000 to flee across the border into Thailand.
The attacks are thought to be the most severe in Karen state for 20 years, a result of the ongoing tensions in Buddhist-majority Myanmar since the army, also known as the Tatmadaw, seized power in a military coup on 1 February.
The Tatmadaw has for many years persecuted the Karen, among them a significant number of Christians, as well the majority-Christian Chin and Kachin, and majority-Muslim Rohingya peoples.