"The United States condemns the attack on the Kurdish Syrian population by Syrian security forces that left three civilians dead and others severely injured," State Department spokesman Sean McCormack said in a statement.

The incidents occurred in the northeastern city of Qameshli, near the border with Turkey, following the March 20 celebrations for Nowruz, the Kurdish New Year.

"We call upon the Syrian government to refrain from using violent measures to repress Kurdish civilians and to open a full, independent investigation of the incident," the statement said.

An official of the Kurdish Yakiti party told AFP last week that Syrian police killed three Kurds in clashes which broke out as the Kurds celebrated their New Year at Qameshli.