The Mexican Interior Minister Miguel Angel Osorio Chong says 14 people were killed in an explosion at Mexican oil giant Pemex's Mexico City headquarters and 80 were injured, reports Reuters.
The death toll could still rise, he told local television.
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It comes after security was stepped up around the country following the Manchester Arena attack which killed 22 people.
A murderer nicknamed 'Houdini' after escaping the death penalty seven times has been given the lethal injection.
The distress signal sparked a police hunt in the area to find the person or group who made it.