An injured woman is transferred after an explosion in Mexico City, capital of Mexico, on Jan. 31, 2013. A powerful blast ripped through the landmark headquarters of Mexico's oil giant PEMEX in Mexico City on Thursday, killing one person, injuring more than 30 others and causing extensive damage to the building, according to local press. [Photo/Xinhua]

An injured woman is transferred after an explosion in Mexico City, capital of Mexico, on Jan. 31, 2013. A powerful blast ripped through the landmark headquarters of Mexico's oil giant PEMEX in Mexico City on Thursday, killing one person, injuring more than 30 others and causing extensive damage to the building, according to local press. [Photo/Xinhua]