Cambodia has accused Thailand's new military rulers of fomenting an exodus of migrant workers which it claimed had caused at least eight deaths and economic hardship for both countries.
Some 188,000 Cambodians -- who help keep major Thai industries afloat but often lack official work permits -- have streamed across the border since the junta warned last week that illegal foreign workers face arrest and deportation.
At a meeting in Bangkok Tuesday, Cambodia's ambassador and Thailand's top foreign ministry bureaucrat agreed to quash "rumours" of a crackdown and to set up a hotline on labour issues.
Ambassador Eat Sophea also dismissed rumours of the shooting and abuse of Cambodian migrants by Thai authorities -- among the factors believed to be triggering the mass departures.
The junta which took power last month has insisted there is no crackdown and tried to calm the panic that has seen the exodus of what could be, by some estimates, the entire undocumented Cambodian population in Thailand.
But if the meeting was intended to mend fences between the two governments, Cambodian Interior Minister Sar Kheng was in more combative mood as he later placed blame for the crisis squarely at Bangkok's door.
"After the military coup in Thailand, the Thai military leaders sent illegal Cambodian migrant workers in a rush without informing and discussing with Cambodia," he said in Phnom Penh, adding that eight people had been killed in traffic accidents linked to the exodus.
"I think that the current leaders of Thai junta must be held accountable for what has happened."
Sar Kheng, who is also deputy prime minister, said Cambodian migrants had helped boost the Thai economy, which is the second-largest in Southeast Asia and draws large numbers of migrants from its neighbours.
"So when they deported them, there will be a problem," he said, adding: "According to my informal information, (Thai) employers have started to protest against the issue."
- 'We did not feel safe' -
At the main border crossing in Poipet -- a bustling town home to several large businesses, casinos and hotels -- around 9,000 Cambodian migrants arrived in Thai military trucks and police cars on Tuesday.
The total number of Cambodians returning from Thailand via Poipet and smaller border crossings has now reached 188,000, said Kor Sam Saroeut, governor of Cambodia's northwestern province of Banteay Meanchey where the main checkpoint is based.
Bun Veasna -- who was employed as a construction and seafood worker in Chonburi province southeast of Bangkok -- was escorted into Poipet by Thai police along with his brother on Tuesday.
"All the Cambodians in my area have returned home. We were scared of being arrested and jailed or killed there. We did not feel safe," the 32-year-old said.
Thailand's military regime has strongly denied it has been forcing Cambodian labourers out of the country and dismissed reports of killings as "groundless".
Since last Wednesday's threat to arrest and deport all illegal foreign workers, the Thai foreign ministry has stressed the "great importance" of the role that migrant workers play in the economy.
In the past Thai authorities have turned a blind eye to illegal labourers drawn from countries including Cambodia, Myanmar and Laos because they were needed when the economy was booming.
But now the country is on the verge of recession after the economy contracted 2.1 per cent quarter-on-quarter in the first three months of 2014.
The coup in Thailand on May 22 followed years of political divisions between a military-backed royalist establishment and the family of fugitive former Thai prime minister Thaksin Shinawatra.
Thaksin was a close ally of Cambodian premier Hun Sen and this may help to explain the exodus of Cambodians, migration policy expert Andy Hall commented.
"I suspect that the Cambodian mass returns compared to Myanmar workers' minimal returns so far reflects the more sensitive political relationship between Thailand and Cambodia," he said.