Thousands of construction workers building a Samsung's factory in Vietnam's northern Thai Nguyen province clashed with security guards on Thursday, leaving 13 people injured, four critically.

Between 3-4,000 of the 10,000 workers building the factory went on the rampage, burning containers used by security forces and destroying cars and motorcycles after security guards beat a worker unconscious.

The worker attempted to enter the site without an entrance card when they were stopped by security guards who beat them with an electric baton, the head of the security for the factory is reported to have said.

Local official Duong Ngoc Long said it took police three hours to stop the riot.

Updated 10/1/14