More than 500,000 people have fled their homes to safety in Thailand and Cambodia since the start of a reignited border conflict, both governments said on Wednesday, surpassing the total number evacuated during similar clashes earlier this year.

"Civilians have had to evacuate in large numbers due to what we assessed as an imminent threat to their safety. More than 400,000 people have been moved to safe shelters" across seven provinces, Thai defence ministry spokesperson Surasant Kongsiri told reporters at a news conference.

"We want to prevent a recurrence of the attacks on civilians we suffered in July 2025."

In Cambodia,"101,229 people have been evacuated to safe shelters and relatives' homes in five provinces," as of Tuesday evening, defence ministry spokeswoman Maly Socheata told reporters.

The Southeast Asian neighbours dispute the colonial-era demarcation of their 800-kilometre (500-mile) frontier, where competing claims to historic temples have spilled over into armed conflict.

This week's clashes are the deadliest since five days of fighting in July that killed dozens and displaced around 300,000 on both sides of the border before a shaky truce was agreed, following intervention by US President Donald Trump.

Both sides blame each other for instigating the renewed fighting, which on Tuesday expanded to five provinces of both Thailand and Cambodia, according to an AFP tally of official accounts.