State officials in the state of Tamaulipas said Thursday that bodies found near Matamoros appeared to be those of three Americans missing in northern Mexico for more than two weeks. Although the identities of the bodies have not yet been officially confirmed by DNA tests, the state’s attorney general, Ismael Quintanilla Acosta, speaking on Radio Fórmula, said that Pedro Alvarado, the father of the three Americans — Erica Alvarado Rivera, 26, and her brothers, Alex, 22, and Jose Angel, 21 — had identified them from photographs of the bodies showing tattoos. Clothing found with the bodies also matched that of the three siblings from Progreso, Tex., who disappeared with a Mexican friend while they were visiting their father in Mexico. Witnesses reported that the four were seized on Oct. 13 by men dressed in police gear.