Tensions between Thailand and Cambodia have escalated again with deadly fighting continuing for a third day. The US has stepped in, urging both countries to "cease hostilities immediately," as clashes have killed at least 10 people—seven in Cambodia and three in Thailand—and displaced more than 500,000. Secretary of State Marco Rubio reminded the nations to follow de-escalation steps from a peace deal brokered by US President Donald Trump last October. Trump promised to "make a phone call" to help end the violence, which is the worst since July when dozens died. Both sides blame each other for sparking the conflict that includes air strikes and artillery fire across six provinces in northeast Thailand and five in Cambodia. Thailand evacuated over 400,000 people, while Cambodia moved 100,000 to safer locations. Thailand’s defence ministry called their military actions "limited in scope" and a last option, stressing "Peace must come with the safety and security of our citizens, full stop." Cambodia accused Thailand of "aggressive military attacks" targeting civilians and sacred border temples. Adding to tension, Cambodia withdrew from the Southeast Asian Games in Thailand, citing concerns from the families of its athletes. UN Secretary-General António Guterres urged both countries to "exercise restraint and avoid further escalation," highlighting the heavy civilian casualties and damage. The border dispute, over an 800km line dating back to French colonial times, reignited violently in July. Back then, Cambodia fired rockets into Thailand, leading to Thai air strikes and five days of deadly fighting. A Malaysian and US-backed ceasefire agreement followed but did not end tensions. With more countries issuing travel warnings for the border, the world watches closely as these neighbours struggle to keep peace.