Myanmar's government initially denied using military jets to hit rebel forces in Kachin. The BBC broadcast a video Wednesday taken by the advocacy group Free Burma Rangers that allegedly shows fighter jets striking rebel territory in the region.
A government spokesman told Voice of America that "training jets" were used to help take control away from the rebel Kachin Independence Organization.
The BBC reported that Myanmar President Thein Sein ordered the military to use only defensive force during operations in the northern state.
Myanmar, a country known also as Burma, has received international praise for a series of political reforms that began with general elections in 2010. Human rights concerns have overshadowed some of the country's political gains, however.
Fighting in Kachin erupted last year, breaking a 17-year truce. In November, the country's president told the U.N. General Assembly that his government was working with various armed groups in the country on cease-fire agreements.