Libyan rebel fighters who captured villages from forces loyal to Muammar Gaddafi have looted shops, burnt homes and beaten people suspected of supporting the Libyan leader, Human Right Watch said.

Since Libya's conflict broke out five months ago, rights groups have focused on allegations of abuses by Gaddafi's forces. But the New York-based group said rebels in the Western Mountains region were committing abuses too.

In the past few weeks, the fighters have advanced to within 100 km of the Libyan capital, capturing several villages which had been used by Gaddafi's forces as bases for attacking rebel-held towns.

"Opposition forces say they are committed to human rights, but the looting, arson, and abuse of civilians in captured towns are worrying," said Joe Stork, deputy Mena director at Human Rights Watch.

"This raises concerns about how civilians will be treated if rebels capture other towns where the government has support," said Stork in a statement from the rebel-held town of Zintan and circulated by the group.

Human Rights Watch researchers said that several houses were set on fire in the village of al-Qawalish after it was taken by the rebels.

They said shops were looted in two other villages, and in a third medical equipment was taken from a clinic.

Forces loyal to Gaddafi appeared to have launched an offensive on Wednesday to retake al-Qawalish, after rebels tried to advance beyond the village to the town of Garyan which controls access to the main highway into the capital.

Researchers also interviewed a resident in the village of Ryayna, who said he knew of several local people who had been beaten by the rebels after they took control, and one who had been shot in the foot by a rebel.

Human Rights Watch, in a report, quoted a local rebel commander as acknowledging there were some abuses, but that these were in direct violation of orders given to fighters not to harm civilians or their property.

The rebel cause in Libya relies heavily on Western assistance and any indication they are failing to respect the rules of warfare could compromise that support.-Reuters