The Sri Lankan government is "slaughtering" civilians with indiscriminate shelling in its effort to eradicate Tamil Tiger rebels in the island's northeast, Human Rights Watch said on Friday.
In a report that followed a covert, two-week fact-finding mission to northern Sri Lanka, the New York-based rights group said those civilians who escaped the combat zone were herded into squalid, military-run internment camps and allowed no freedom of movement.
"Sri Lankan forces are shelling hospitals and so-called safe zones and slaughtering the civilians there," said, James Ross, legal and policy director at Human Rights Watch.
"This 'war' against civilians must stop," Ross said.
Tens of thousands of non-combatants are believed to be trapped in the narrow strip of coastal jungle where the Sri Lankan military has cornered the rebels from the Liberation Tigers of Tamil Eelam (LTTE).
The government says the Tigers are using the civilians as shields, while the rebels say they are protecting them.
The report was compiled from the testimony of civilians who had managed to flee the fighting. The Sri Lankan government has barred journalists and rights monitors from the war zone.
Human Rights Watch condemned the LTTE for preventing civilians from leaving the war zone and subjecting those in areas under its control -- including children -- to forced recruitment and forced labour on the battlefield.
"With each battlefield defeat, the Tamil Tigers appear to be treating Tamil civilians with increased brutality," said Ross.
One local resident interviewed by the fact-finding team described how the Tigers took people to the front lines and made them dig bunkers and collect weapons from dead fighters on both sides.
"About 25 of my neighbors were killed while doing this work. They did not receive any training," the resident said. "The LTTE cadres fetched them from their homes and the next day brought their dead bodies back."
According to the report, those managing to flee the fighting face renewed hardship in military-run "welfare villages".
"They are held by the government in squalid military-controlled camps and hospitals with little access to the outside world," said Ross.
"The government seems to be trying its best to keep its role in their ordeal away from public scrutiny," he said, adding that any apparent LTTE suspects arriving at the camps were secretly taken away and often never seen again.
The plight of the civilians was highlighted Thursday by UN humanitarian chief, John Holmes, who was in Sri Lanka for a three-day visit.
The International Committee of the Red Cross has warned of an "unfolding catastrophe" with trapped civilians short of food, medicine and shelter.
The Sri Lankan government has rejected international appeals for a ceasefire, insisting that they intend to crush the Tigers as a fighting force.