Two Myanmar towns on a lucrative trade route to Thailand have been besieged by fighting despite a truce declared after last month's massive earthquake, residents said on Thursday.

A 2021 coup sparked a multi-sided civil war between Myanmar's military, pro-democracy guerrillas and ethnic rebel groups that have long been active in the country's fringes.

Four years of conflict have spurred mass displacement and poverty, and much of the fighting has focused on trade routes where combatants run tollgates to bolster their war chests.