Myanmar's army launched a new offensive Wednesday against ethnic Kachin rebels in the steep hills around their headquarters on the Chinese border, killing over 20 people in a mortar attack and skirmishes that lasted the whole day, rebel officials said.
According to ABC news, most of the casualties occurred when government troops hit an officer training academy used by the rebels near the frontier city of Laiza, leaving 22 insurgents dead and 15 more wounded, according to La Nan, a spokesman for the Kachin Independence Army.
La Nan said the army fired from a nearby hilltop about 50 kilometers (30 miles from) outside Laiza. He said at least one Kachin villager was also killed in skirmishes in the area that began in the morning.
Myanmar's government could not immediately be reached for comment.
Fighting between the army and Kachin insurgents broke out in 2011, ending a truce between the two sides that had held for 17 years. President Thein Sein's government has agreed to tentative peace deals with 14 insurgent factions since then, but has not been able to secure a deal with the Kachin or broker a wider truce encompassing all armed groups.
After a major offensive near Laiza in December 2012, hostilities eased, but sporadic, low-level clashes have continued.