Ciudad Juarez, Mexico (CNN) -- An explosion rocked a candy factory in the Mexican border city of Juarez on Thursday, injuring dozens and killing at least one person, officials said. Search crews were still combing through the rubble hours after the blast, the city's top civil protection official told CNN affiliate FOROtv. At least one person was confirmed dead, Civil Protection chief Fernando Motta Allen said. At least 42 employees were injured, 11 seriously, according to Efren Matamoros, another Civil Protection official. The explosion caused part of the roof to collapse at the Blueberry candy factory. Preliminary reports indicate that an oven installed several months ago exploded, Matamoros said. Ciudad Juarez is across the border from El Paso, Texas. CNN's Eduardo Aragon, Elwyn Lopez and Catherine E. Shoichet contributed to this report.
NEW: An official says at least one person was killed in the blast . At least 42 people are injured after a factory explosion in Ciudad Juarez, an official says . The blast at the Blueberry candy factory caused part of the roof to collapse . Preliminary reports indicate an oven explodes, the official says .