WATCH: US man takes off pants as cellphone catches fire in pocket

In an embarrassing moment, a man in the US was forced to take off his pants while shopping as his cell phone caught fire in his pocket.

The incident took place at a Costco shop in Puyallup city, 35 miles south of Seattle. 

"He had taken the pants off and tied the jacket around his waist. And I thought that was unusual, and I looked down, and then there was what looked like to be what's left of a cell phone," said Everett Tyrrell, an eye witness who had gone to the shop.

"That was very weird to me. I'd never seen anything like that in my life. It's amazing how much heat must have been generated to cause all that smoke from that small item," Tyrrell was quoted as saying by kiro7.com, a CBS-affiliated television station in Seattle.

He said the LG phone was barely recognisable and smoke had billowed through the hardware aisle.

A store manager said when he went to the scene, he found the man with his pants off and a cell phone on the ground, still smoking.

An employee had used a fire extinguisher on the phone, the manager said, adding that the phone was reduced to ashes and left a burn mark on the floor.

The victim was not hurt and was provided a new pair of pants by the Costco staff, manager said.

It was not clear how the fire had started.