It has been revealed that a deadly blast that killed at least 37 people at the headquarters of the Mexican state oil company Pemex was caused by a build-up of gas.<br /><br />Officials say no trace of explosives was found at the site of the explosion in Mexico City. <br /><br />The gas is believed to have been methane.<br /><br />The explosion, last Thursday afternoon, prompted speculation about sabotage.<br /><br />...<br />http://www.euronews.net/
