Al-Jazeera news channel says Syrian authorities have confirmed the detention of one of its reporters missing since Friday.

Dorothy Parvaz traveled to Syria on Friday to report on the political turmoil there.

Parvaz works for the English-language arm of the news network. She holds U.S., Iranian and Canadian citizenship and was once a reporter and columnist for the Seattle Post-Intelligencer.

Al-Jazeera called on Syrian authorities to release Parvaz immediately.

Parvaz's detention highlights the worsening relations between Syrian authorities and the Qatar-based channel.

Al-Jazeera reporters were allowed to stay in Syria as other reporters were expelled several weeks ago, but last week the station said it was scaling back its Syrian operations, citing harassment by security forces.