Myanmar has been in turmoil since a military coup deposed Aung San Suu Kyi's administration in February 2021.

On Sunday a convoy of several vehicles travelling in Taunggyi township in eastern Myanmar's Shan State was attacked by an unknown armed group, a foreign diplomat based in Yangon told AFP on condition of anonymity.

"A convoy with some diplomats was attacked yesterday morning," the source said.

The convoy was carrying diplomats from the embassies of Indonesia and Singapore and officials coordinating humanitarian relief from the Association of Southeast Asian Nations (ASEAN) regional bloc, they added, noting that no casualties were reported.

A senior military official who did not want to be named confirmed to AFP that a convoy had been fired on.

The officials and diplomats had been travelling Sunday to "hand over humanitarian aid," Indonesian President Joko Widodo said on Monday.

"Regretfully on their way, there was a shootout," he said, without giving any further details.

AFP has asked the Indonesia and Singapore embassies in Yangon for comment.

Southern Shan state -- home to Taunggyi township -- has seen relatively little of the violence that has ravaged Myanmar since the coup more than two years ago.

But in March around 30 people sheltering at a monastery in the same state were killed, with the junta and anti-coup fighters trading accusations over the massacre.

Southeast Asian leaders will this week meet in Indonesia for a summit expected to be dominated by the Myanmar crisis.

Long slammed by critics as a toothless talking shop, ASEAN has led diplomatic attempts to resolve the bloody crisis.

But its efforts have stalled as the junta ignores international criticism and refuses to engage with its opponents, which include ousted lawmakers, anti-coup "People's Defence Forces" and ethnic minority armed groups.