Soldiers joined emergency rescue teams to search for people feared trapped under debris after an explosion in Mexico City.
The blast in a neighbouring building hit the headquarters of state-owned oil giant Pemex, killing at least 25 people and injuring more than 100.
Interior Minister Miguel Angel Osorio Chong told Reuters that the number of casualties is expected to rise.
He said at least one person had been pulled out alive.
A paramedic at the scene told Reuters that as many as 100 people could be trapped.
The blast happened shortly before many workers were due to end their shifts at Pemex, making the area particularly busy.
More top news
The Hollywood star showed the emotional first trailer for the film to conference attendees in Las Vegas.
Three Court of Appeal judges are analysing the latest stage of a life-support treatment dispute.
Ms Markle joined Harry and William at services in London to honour the fallen.