Tens of thousands of people gathered in Cambodia’s capital Phnom Penh on Wednesday for a march to show their solidarity with the government and military, amid soaring tensions with neighboring Thailand following a border row that erupted last month.

The reescalation of conflict was sparked on May 28, when a Cambodian soldier was killed in an early morning clash between both nations’ troops, in an area called the Emerald Triangle—the shared border between Thailand, Cambodia, and Laos. The area remains disputed as both Thailand and Cambodia lay claims to parts of the region.

Thai marines opened a border checkpoint in Chanthaburi province on Friday night to allow the emergency medical transfer of a critically ill Cambodian woman suffering from sepsis.