GIA LAI PROVINCE, Vietnam — The communist Vietnamese government arrested two Montagnard Christian men in the Central Highlands region, the latest detentions in a long-running campaign against ethnic minority Christians who refuse to join state-controlled churches.

Pastor Siu Yúi, 68, and church member Siu Dok, 40, were taken into custody in Gia Lai Central Province and charged with using religious teachings to mobilize ethnic minority communities toward separatism and independence, according to Christian Solidarity Worldwide.

“Please pray for these brothers, and for the countless other Montagnard Christian brethren inside Vietnam, living as refugees in Thailand, and scattered around the globe facing persecution,” an International Christian Concern staffer said.

The arrests follow a pattern of enforcement by Hanoi against Montagnard Christians — an indigenous highland population with deep Protestant roots — who worship outside the structures sanctioned by Vietnam’s one-party state. The campaign has extended beyond Vietnamese borders: a few months ago, Montagnard Christian leader Y Qinh Bdap was controversially extradited from Thailand to serve a prison sentence in Vietnam, a case that drew condemnation from international religious-freedom advocates.

Vietnam remains on the U.S. Commission on International Religious Freedom’s watch list for severe violations of religious liberty. The Montagnard communities in the Central Highlands, along with diaspora populations in Thailand and elsewhere, face sustained pressure from Vietnamese security services targeting unregistered worship. USCIRF’s next annual report is expected to address the ongoing detention of religious prisoners in Vietnam.