Global chemical weapons watchdog, the Organization for the Prohibition of Chemical Weapons (OPCW), confirmed in a statement on Wednesday that its latest report shows "compelling confirmation" that a toxic chemical, almost certainly chlorine, was used "systematically and repeatedly" as a weapon in attacks on north Syrian villages earlier this year.

"The descriptions, physical properties, behavior of the gas, and signs and symptoms resulting from exposure, as well as the response of patients to the treatment, leads the mission to conclude with a high degree of confidence that chlorine, either pure or in mixture, is the toxic chemical in question," OPCW spokesman Michael Luhan said in the statement.

The OPCW's report does not, however, assign blame for the use of chlorine to any specific group.

New allegations

The report's conclusions were based on dozens of interviews with victims, doctors, eye-witnesses and analyzed documents including videos and medical records, which were obtained by means of a fact-finding mission, investigating alleged attacks in Syria from earlier this year.

The attacks actually took place during the mission by Damascus and OPCW to remove Syria's stockpile of chemical weapons. Syria didn't, however, have to declare its stockpile of chlorine, as despite being a toxic industrial gas, it is not specifically classified as a chemical weapon unless used offensively.

The probe will now continue following "a spate of new allegations" in August.

An initial report by the same mission in June also said that evidence "lends credence" to the conclusions that chlorine was likely to have been used as a weapon in Syria.

In May, Human Rights Watch said that it too had strong evidence that, in April, Syrian army helicopters dropped bombs containing chlorine on the same rebel-held villages mentioned in the latest OPCW report.

UN reports chemical use

Last month, the independent United Nations commission on Syrian war crimes also reported that Assad's government had used chlorine on civilian areas on eight different occasions in April.

"Reasonable grounds exist to believe that chemical agents, likely chlorine, were used on (northern Syrian villages) Kafr Zeita, al-Tamana and Tal Minnis in eight incidents within a 10-day period in April," the commission said.

Both Assad's regime and anti-government rebels rebels have accused each other of using chemical agents, including chlorine, since the uprising began in March 2011.

ksb/hc (AFP, AP, dpa)