An explosion at a chocolate factory in West Reading, Pennsylvania has left five people dead and two individuals missing.

The explosion took place just before 5pm on Friday in the small town about 60 miles from Philadelphia at the RM Palmer Co plant in Berks County, according to WPVI.

One person has been found alive during the ongoing search efforts and ten have been taken to area hospitals.

West Reading Borough Police Chief Wayne Holben said the authorities “will not rest until every single person affected by this tragedy has been accounted for”.

Heat imaging gear and dogs have been used in the search following the blast that completely destroyed the building and damaged another nearby. Chief Holbena added that heavier equipment is now being used to carefully remove debris from the area in the search for possible survivors.

Diana Cedeno remains missing. Her cousin Danny Wyatt told WPVI that “she’s a God-fearing woman. She’s beautiful, she’s a great person”.

He added that she had just started her shift when the blast occurred.

“We’re holding onto faith and hope. It just gets more antagonizing as time goes on,” he said.

Witnesses say they heard a loud blast, followed by a blaze.

Kristen Wisniewski, who lives three blocks away from the factory, told WPVI that “it was the loudest thing I’ve ever heard in my life”.

“It literally felt like the ground fell out from underneath you. The whole house shook and my dogs froze, they couldn’t move, it was scary,” she added.

Officials have said that one of the RM Palmer buildings has been destroyed while another has been damaged.

Mayor Samantha Kaag said, “it’s pretty leveled, unfortunately there’s not too much to be able to salvage from it”.

“In the front, with the church and the apartments, the explosion was so big that it moved that building four feet forward,” she added, according to WPVI.