U.S. immigration authorities have detained Salah Sarsour, a Palestinian American and longtime legal resident, sparking concern after the prominent mosque leader was taken into custody earlier this week, officials said Thursday.

ISM, which is Wisconsin's largest mosque, said Sarsour, 53, is a legal permanent resident who has lived in the ​U.S. for over three decades and was detained on ​Monday. ⁠He grew up in the Israeli-occupied West Bank.

"He was pulled over while driving by over 10 ICE agents with no cause," a page on the mosque's website said, adding he was taken out of the state to a detention facility in Chicago before being transferred to a detention center in Indiana.

ICE and the Department of Homeland Security, of which ICE is a part, did not respond to a request for comment.

The Milwaukee Journal Sentinel cited Othman Atta, the executive director of the mosque, as saying that deportation documents focused on Sarsour's ⁠arrest ⁠by Israeli authorities as a teenager living in the West Bank to argue he allegedly provided material support for extremists.