About 100 members of a polygamist sect thanked volunteers for their support during a gathering in Texas to mark the anniversary of a raid that resulted in one of the country's largest child custody cases.

Fundamentalist Church of Jesus Christ of Latter Day Saints spokesman Willie Jessop says the church returned to Fort Concho on Friday to thank those who "came to the aid of our people."

State officials raided the compound in April 2008 and removed 439 children amid allegations of sex abuse. All but one of the children have been returned to their parents.

The state says it believes abuse occurred but says the children are now safe.

Twelve members, including sect prophet Warren Jeffs, face charges including sexual assault.