The Myanmar junta on Saturday accused an armed ethnic group of attacking a vehicle convoy containing Chinese military personnel who were travelling to a meeting on border security, a claim the rebels denied.
Myanmar has been in chaos since the military ousted democratically-elected civilian leader Aung San Suu Kyi from office in a 2021 coup.
Fighting between the junta and opponents has ravaged vast swathes of the country.
On Tuesday, a vehicle convoy containing Chinese military representatives and Myanmar counterparts headed to Myitkyina in northern Kachin state came under fire.
A vehicle that was second in line was shot five times, the junta said.
Myanmar security forces retaliated.
"We can confirm that (Kachin Independence Army) members attacked the convoy," junta spokesman Zaw Min Tun said in an audio message.
The junta said no one was wounded or killed in the incident.
But the KIA denied responsibility.
"KIA did not attack any convoy," KIA colonel Naw Bu told AFP, adding there had been heavy fighting in the area, near where the convoy was attacked, since Monday.
Comment has been sought from China's foreign ministry.
In October last year, dozens of people died when the Myanmar military conducted air strikes on a KIA concert.
More than 3,700 people have been killed in the military's crackdown on dissent since the coup, according to a local monitoring group.