Syria's armed opposition is carrying out serious human rights abuses, including kidnapping, torture and execution of security force members and government supporters, a rights group said Tuesday.
"The Syrian government's brutal tactics cannot justify abuses by armed opposition groups," said Sarah Leah Whitson, Middle East director of Human Rights Watch (HRW).
"Opposition leaders should make it clear to their followers that they must not torture, kidnap, or execute under any circumstances."
The New York-based watchdog said that while the one-year revolt in Syria had started as a largely peaceful uprising, it had transformed into an armed insurgency, especially since early February, when the government launched large-scale attacks against opposition strongholds throughout the country.
It said that many anti-government groups reportedly carrying out abuses did not appear to belong to an organised command structure or to be following orders by the Syrian National Council (SNC), the main opposition group.
"It is imperative for armed elements of the Syrian opposition to protect human rights," Whitson said. "They need to make it clear that they envision a Syria that turns the page on Assad-era violations and welcomes all, regardless of their religious group or background, without discrimination."
The rights group said it had documented cases of kidnappings, torture and executions by opposition groups, often with a sectarian motive.
"Some of the statements collected suggest that certain armed attacks by opposition groups were motivated by anti-Shiite or anti-Alawite sentiments arising from the association of these communities with government policies," HRW said.
Syria's population of 23 million is predominantly Sunni Muslim, while the ruling Alawites, an offshoot of Shiite Islam, form the minority.
The regime of President Bashar Al-Assad claims that foreign-backed terrorists are behind the revolt that began last March.
It has ignored a chorus of international condemnation against the brutal government crackdown to crush the uprising, in which rights activists say more than 9,100 people have been killed.