By Andrew Harding
BBC News, Burma
Thousands of families are reported to be on the run in the hills of eastern Burma because of a government offensive against ethnic Karen rebels.
As many as 15,000 people are thought to have left their homes
Burma's military regime is accused of widespread human rights abuses against civilians in the area.
Human rights campaigners describe it as ethnic cleansing and are calling for foreign intervention.
Karen ethnic minority groups have been battling the regime for decades to achieve greater autonomy.
Slipping across the Burmese border by boat, then hiking through the jungle to a remote valley, we met 700 weary civilians who are now in hiding.
The Khu family had arrived a day earlier trekking for a month from their village.
The father, Sawmaw, said Burmese government troops had burned every house and killed some of his neighbours.
Almost everyone we spoke to gave detailed and credible evidence against government troops
The family then fled with a bag of rice and a blanket. Thirteen-year-old Sayploe helped carry his younger brothers.
Another man, Sawwysher, told me Burmese soldiers had ordered his village to watch them torture a suspected rebel.
They tied him to a tree and beat him to death.
In the past few months, government troops have launched a major new offensive.
That has triggered an exodus of civilians, perhaps as many as 15,000, who are either hiding in the jungle or heading for the border with Thailand.
Malaria and landmines are a constant danger.
Little outside help has reached them.
When we left, the Khu family were washing the grime off their clothes.
They have no idea when, or if, they will go back to their village.
For years, the Burmese army has been accused of terrorising civilians.
Reports of rape, executions and forced labour are common.
Almost everyone we spoke to gave detailed and credible evidence against government troops.