The rescue workers were 13 miles from Lashio, the largest town in Shan State, where ethnic armed groups have been fighting for greater autonomy from the central government, when their convoy came under attack.
"Our chairman was shot by a sniper – it hit the side of his head. After that, the ambulance was hit by an RPG and the car turned over and he died," said Aung Kyaw Moe, a member of the Lashio Youth Charity Association who said he survived the assault.
He blamed insurgents from the Northern Alliance, a group of ethnic armies battling government troops, for the attack.
Photos and video published by local media on Saturday showed a vehicle marked with the youth group’s name turned on its side, its windows riddled with bullet holes.
Tensions in the region have risen since Thursday, when the Northern Alliance staged attacks in the region including on an elite army college that killed more than a dozen people, mostly security forces personnel.
Army spokesman Tun Tun Nyi said insurgents attacked a petrol station and a bridge in another location on Saturday morning, and rescue workers were traveling there when they were attacked.
A spokesman for the Arakan Army, one of the groups in the Northern Alliance, referred questions to the Ta'ang National Liberation Army, another group in the alliance. A spokesman for the TNLA did not answer phone calls seeking comment.
The escalation in hostilities in Myanmar’s fractured north is another setback for civilian leader Aung San Suu Kyi’s bid bring peace to the country amid a stuttering transition from full military rule.
The Nobel laureate came to power following a landslide election win in late 2016, vowing to prioritize peace talks between ethnic armed groups, the military and civilian government.
But the conflict has escalated in northern Kachin and Shan states as well as the western Rakhine region on the border with Bangladesh.