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Angry families storm a news conference demanding to know about missing relatives

Authorities need to learn from 'extremely profound' lessons, Chinese President says

Tianjin, China CNN  — 

Crews searched for an unknown number of civilians and soldiers Saturday who are believed trapped by multiple explosions that killed at least 112 people this week in this eastern Chinese city.

As of Sunday morning, more than 50 people have been rescued in Tianjin, city government spokesman Gong Jiansheng said. They include a 19-year-old firefighter who lay on the ground for hours with burns and a cracked skull until he was found, officials said.

Relatives of some of the 95 people missing, mainly firefighters, stormed an official news conference demanding to know the whereabouts of their loved ones. Families wrote the names of missing people on posters lining a street outside a temporary shelter near the rescue site.

On Saturday, fires sent plumes of black smoke skyward near where explosions devastated a chemical warehouse in Tianjin on