In another gay marriage split, Mennonite Church USA loses a sixth of its members to the conservative-leaning Lancaster group.

Two years after deciding to leave the Mennonite Church USA (MC USA) related to disagreements over same-sex marriage, a conservative-leaning group of nearly 180 churches made their split official at the start of 2018.

The biggest of MC USA’s 25 conferences, the Lancaster Mennonite Conference has rallied support following its decision to end its 46-year affiliation with America’s top Anabaptist denomination.

Since 2015, 29 congregations have joined the Lancaster conference; about of half of them came from the nearby Franklin Conference, which also voted to split from the MC USA, according to Mennonite World Review.

Based in Lancaster, Pennsylvania, most of the conference’s congregations are located in the Northeast, but the group is expanding geographically. L. Keith Weaver, conference moderator, told Lancaster Onlinethat in the coming months 14 Mennonite congregations in the Dominican Republic are also expected to join.

Eight congregations that formerly belonged to Lancaster ultimately wanted to stay in the denomination. They joined Atlantic Coast Conference, which remains a part of the MC USA, prior to the January 1 split, the Pennsylvania newspaper reported.

Lancaster’s departure cuts overall MC USA membership by about a sixth, according to 2016 figures reported by Mennonite World Review. At the time, the denomination included about 79,000 members, nearly 14,000 of which belonged to congregations in the Lancaster conference.

Though the MC USA continues to define marriage as “a covenant between one man and one woman for life” in its confession of faith, some opponents to same-sex marriage fear its stance is loosening.

The denomination has voted down a proposal to affirm same-sex marriage, but …