New border restrictions are in place for travellers trying to get from Thailand to Cambodia, with tourists now blocked from making the crossing by land.
Thailand's prime minister has announced the new rules as relations between the two countries continue to deteriorate amid a border dispute.
The two countries have announced tit-for-tat restrictions following the death of a Cambodian soldier in a contested border area late last month.
While the two sides have agreed to de-escalate their dispute, they continue to implement or threaten measures that have kept tensions high.
Thailand's Prime Minister Paetongtarn Shinawatra said on Monday Thailand would boost screening at land borders and block departing tourists.
Ms Paetongtarn said that only students, medical patients and others who need to purchase essential goods would be allowed to enter or leave Thailand.
She said the measures were aimed at blocking people heading toward Cambodia's lucrative casinos, but it appeared that all tourists would be blocked.
The Thai army said in a statement that it had implemented the measures at every land border checkpoint between Thailand and Cambodia in five provinces, and that it was stopping all crossings except for people with essential needs.
Cambodia, for its part, has boycotted some Thai internet services, and blocked electricity and fuel supplies from Thailand in response to the border dispute.
Prior to the boycott, Cambodia imported 30 per cent of its petrol and other fuel from Thailand.
Ms Paetongtarn also said Thailand would consider blocking exports that could facilitate scam operations in Cambodia and would coordinate with other countries and international agencies to crack down on cybercrime based in South-East Asia.
Thailand this year implemented measures aimed at cracking down on online scam operations in neighbouring Myanmar, severing electricity, internet and gas supplies to border towns where the scams were based.
Ms Paetongtarn's comments suggested Thailand would soon impose similar measures aimed at similar scam operations in Cambodia.
An April UN report named Cambodia as a hub for scam operations in which workers go online to lure victims through false romantic ploys, bogus investment pitches and illegal gambling schemes.
Ms Paetongtarn has been attacked over her perceived soft stance toward Cambodia, especially by right-wing nationalists who are longtime foes of her father, former prime minister Thaksin Shinawatra.
A phone call leaked last week between her and Cambodian Senate President Hun Sen, the former prime minister who ruled Cambodia over four decades, sparked outrage and calls for her resignation.
Critics said she tried to appease Hun Sen, a longtime friend of her father, and made Thailand look weak by calling a Thai army commander in charge of the disputed border area as "an opponent".
Several nationalist activist groups have planned a rally this week to demand the Thai prime minster's resignation.
AP/ABC
