A court in northwestern Vietnam has sent eight ethnic Hmong tribesmen to prison for up to 30 months, for what the government describes as disturbing social order and inciting separatist unrest last year. Supporters say the minority Christian defendants were participating in a religious convocation.

The official Vietnam News Agency, in a report Wednesday, described the defendants as “illiterates” who “admitted to not knowing the illegal nature of their activities.” Presiding Judge Phan Van Nam is quoted by the Associated Press as saying police are still hunting for three ringleaders.

The prison terms come nearly a year after international media reported widespread unrest in the region near the border with Laos. Those reports, backed by the government, said thousands of evangelical Hmong had gathered in Dien Bien province waiting for their God to appear to take them to the promised land in May.

The government launched a crackdown after additionally accusing leaders of advocating for an independent Hmong kingdom.

Some Hmong advocacy groups said more than 60 people were killed and hundreds of others injured in the crackdown. With international reporters barred from the region, there was no independent confirmation of those claims.

The Hmong are ethnically distinct from the Vietnamese and have long chafed under Hanoi's rule. Many fought alongside U.S. troops in the Vietnam War.