Thailand said Tuesday that Cambodia violated their hours-old cease-fire that ended days of fighting between the neighbors over their disputed border.

State Department officials are currently in Malaysia to assist in the ceasefire talks between Thailand and Cambodia, Secretary of State Marco Rubio announced. The two Southeast Asian countries have been involved in a deadly border conflict since late last week,

The leaders of Cambodia and Thailand have agreed to “an immediate and unconditional ceasefire” following five days of clashes at the border. The ceasefire is set to come into effect at midnight, bringing an end to their deadliest conflict in over a decade,