MEXICO CITY, Mexico (CNN) -- A truck carrying more than 25 tons of dynamite exploded Monday in northern Mexico, killing at least 23 people and injuring more than 140, a government spokesman said. Of the 140 injured, 30 suffered critical wounds and five were listed in extremely critical condition, said David Aguisn, spokesman for Humberto Moreira, the governor of the state of Coahuila. Notimex, Mexico's official news agency, reported at least 30 people were killed in the blast at a factory near Monclova -- about 125 miles (200 kilometers) northwest of Monterrey. Three Mexican reporters were among those killed, according to Notimex. Video footage showed the burned-out, mangled shell of the truck and nearby cars damaged by the blast. Aguisn said that there is no indication of foul play. The cause of the explosion is under investigation. E-mail to a friend . CNN's Ariel Crespo contributed to this report.
Truck was carrying more than 25 tons of dynamite . At least 140 people injured in the blast, government spokesman says . No foul play suspected, spokesman says; cause under investigation . Mexican news agency reports higher death toll of 30 .