"The parties had organised a sit-in in protest at a decree forbidding the sale without prior authorisation of land and property in border areas," the National Organisation of Human Rights in Syria (NOHRS) said in a statement.

"Police dispersed the demonstrators and detained dozens before removing them to an unknown location," it added, listing the names of 18 of those held.

The NOHRS called on the authorities to "free demonstrators who were exercising their constitutional right to protest."

More than 1.5 million Kurds live in Syria, mainly in the north in areas bordering Turkey and Iraq. They comprise nine percent of the population and have long sought official recognition of the Kurdish language and their culture.