A soldier stands guard near the headquarters of state oil giant Pemex in Mexico City January 31, 2013. A powerful explosion rocked the Mexico City headquarters of state oil giant Pemex on Thursday, killing at least 14 people and injuring 100 others.The blast hit the lower floors of the downtown tower block, throwing debris into the streets and sending workers running outside. Interior Minister Miguel Angel Osorio Chong said the blast killed at least 14 people and injured 100. It was not yet clear what caused the explosion, and the death toll could still rise, he added. REUTERS/Alejandro Dias (MEXICO - Tags: DISASTER ENERGY POLITICS MILITARY) Published: Úno. 1, 2013, 2:16 dop. | Foto: Reuters