BANGKOK, June 1 (AP) — Thailand said Friday that neighboring Myanmar has apologized after one of its fighter jets crossed into Thai airspace on a bombing run along the border, forcing authorities to evacuate hundreds of schoolchildren and scramble air force jets to the area.

Prime Minister Prayuth Chan-ocha said Thailand did not want to escalate the incident, which took place on Thursday over Phop Phra district in Thailand’s Tak province. Local authorities evacuated villages and schools in the area. Teachers at Wale School led over 200 elementary and middle school students from their classrooms to fortified buildings inside the school grounds for safety.

Video obtained by The Associated Press shows what appears to be a MiG-29 making several circles into Thai airspace over villages and schools before firing on the Myanmar side. Myanmar’s military has been fighting ethnic Karen guerillas on its side of the border with Thailand.

“The military attaches have spoken to each other, and they have apologized, and our foreign ministries have talked. This may seem like a serious incident, but it depends on us if we want to escalate this. Currently the two sides enjoy a good relationship and are able to talk,” Prayuth told reporters at a public appearance.

He added that “the most important thing is that we do have a capability to defend our sovereignty. We also must plan for the strength and modernity (of our defense) in the future. This is not a major issue.”

Thailand’s air force dispatched two U.S.-made F-16 fighter jets to the area where the Mig-29 had been flying. Thai military authorities said the Myanmar jet had been providing air support to a military ground operation inside Myanmar taking place just a kilometer away from the border. Thailand said more than 500 people crossed over to the Thai side during the incident.

Fighting between Myanmar government forces and ethnic guerrillas, many of whom live in border areas, has continued for decades but has intensified since the military seized power in February last year from a democratically elected government. The fighting has sent waves of refugees from Myanmar fleeing into Thailand. They are then sent back when the fighting recedes.