The leaders of Cambodia and Thailand agreed to a ceasefire in a bid to bring an end to their deadliest conflict in more than a decade.

PUTRAJAYA, Malaysia (AP) — Thailand and Cambodia have agreed to an “unconditional” ceasefire starting at midnight, Malaysian Prime Minister Anwar Ibrahim said Monday, a significant breakthrough to resolve five days of deadly border clashes that have killed dozens and displaced tens of thousands of people.

U.S.-backed talks to end the border war, in which militaries have killed dozens of people and displaced hundreds of thousands, began on Monday in Malaysia.