Only students, medical patients and people purchasing essential goods will be allowed to enter or leave Thailand under the new rules.

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.

Thailand announced a raft of security and trade measures to cripple transnational crime syndicates in Cambodia, as Prime Minister Paetongtarn Shinawatra seeks an upper hand in a simmering border dispute with its neighbor.