An American journalist reporting on live TV has been roughed up by locals in China angry at reporting on a series of deadly explosions that have killed 17 and injured hundreds.

CNN journalist Will Ripley was reporting outside a hospital in Tianjin this morning, as relatives of those injured waited for news on their loved ones.

"A man has been loudly sobbing for several minutes now, he keeps saying 'why would God take my daughter away?'," Ripley says, speaking into his handheld camera.

"It's really heartbreaking to see."

As CNN anchor Michael Holmes asks Ripley to describe the scene of the explosions, at least three men appear, shouting and grabbing at Ripley's camera.

Ripley's attempts to calm the mob can be heard as he is manhandled.

"It's okay, it's okay," he says.

The footage becomes increasingly shaky before cutting out entirely seconds later.

"Tempers obviously running high after an awful night in Tianjin," Ripley wrote on Twitter just after the incident.

"I'm fine. A lot of people here aren't."

A series of massive explosions rocked a container port in Tianjin overnight, with 17 confirmed dead and more than 400 injured, many with serious burns.

The blasts reportedly occurred where highly-flammable material was being stored.