Cambodia has blamed Thailand's ruling military for sparking an unprecedented exodus of Cambodian migrant workers.
Interior Minister Sar Kheng said the Thai army "must be held responsible".
Officials say more than 180,000 Cambodians have fled across the border since the junta announced a crackdown on illegal migrant workers last week.
The Thai military has since stressed that it was only targeting illegal immigrants, but the flow of returnees has continued.
Earlier in the week, Cambodian diplomats had stressed that they were working with their Thai counterparts to quash false rumours of a wider crackdown on foreign workers.
But Sar Kheng told a student graduation ceremony in Phnom Penh that the problems were all down to the junta.
"The army rushed to deport workers who are considered illegal without prior notice or discussion with Cambodia," he said.
"I think the current Thai army leadership must be held responsible for all the problems that have occurred, including the loss of life."
Six Cambodians and their Thai driver were said to have been killed on the weekend as their truck overturned on the way to the border.
The Cambodian government is struggling to deal with the sudden influx.
Hundreds of military trucks have been commandeered to take the workers away from the border.
And officials are working on job-creation schemes.
The precise reason for the exodus is not fully understood.
Many of the returnees have said they feared for their lives.
"All the Cambodians in my area have returned home," Cambodian Bun Veasna told the AFP news agency.
"We were scared of being arrested and jailed or killed there. We did not feel safe."
Cambodians are often viewed as suspect because of support their government has given to the controversial former Prime Minister Thaksin Shinawatra.
Mr Thaksin was ousted in a coup in 2006, and his sister Yingluck was similarly unseated as prime minister by the military last month.
Thai industry depends on the two to three million migrants who have come from neighbouring countries.