Renewed border clashes between Thailand and Cambodia have resulted in at least 13 deaths and forced tens of thousands to flee, undermining a US-backed ceasefire. Cambodian military reports nine civilian deaths, while Thailand reports four soldiers killed. Both countries vow to continue fighting, with Cambodia's Hun Sen asserting the need to defend territory. Evacuations are underway, with thousands displaced and temporary shelters set up. The US urges an end to hostilities and compliance with peace accords.