McALLEN, Texas (AP) — A humanitarian organization in northeastern Mexico said it did not create flyers urging migrants to vote for President Joe Biden that were filmed at its shelter in a viral video that sparked a firestorm of conservative outrage this week.

Accusations that Resource Center Matamoros was encouraging noncitizens to vote gained momentum after online posts displayed Spanish-language flyers instructing migrants to vote illegally for Biden once they arrived in the U.S. The flyers contained the logo of the organization, but it was not clear who created or posted them. Videos showed them on the interior walls of portable toilets at the center’s shelter near Mexico’s border with Texas.

Resource Center Matamoros founder Gaby Zavala told The Associated Press the organization doesn’t know who made the flyers and said her group “does not encourage immigrants to register to vote or cast ballots in the U.S.”