Taiwan's Foxconn Technology Group closed its Taiyuan plant in northern China on Monday after a brawl involving possibly thousands of workers began in dormitory facilities early in the morning.
The Taiyuan plant, which employs about 79,000 workers, makes parts for automotive electronics and assembles various electronic devices, according to Foxconn spokesman Louis Woo.
"The fight is over now ... we're still investigating the cause of the fight and the number of workers involved," said Woo, adding that "involving a couple thousand workers is possible".
Woo said the fight happened in the workers' dormitory facilities and said the company would issue a statement later on Monday.
China's Xinhuanet.com, operated by the Xinhua News Agency, said about 10 people were hurt in the fighting, citing police.
Foxconn, the trading name of Hon Hai Precision Industry Co and the world's largest contract maker of electronic goods, has seen a few violent disputes at its sprawling plants in China, where it employs a total of about 1 million workers.
By late morning, Hon Hai shares were down 1.14 percent, lagging the broader market's decline of 0.28 percent.
In June, about 100 workers went on a rampage at a Chengdu plant in southwestern China. The company has faced allegations of poor conditions and mistreatment of workers at its China operations, and has been spending heavily in recent months to improve the work environment and to raise wages.
A staff member at the Taiyuan plant said he was told the plant could be closed up to two to three days for police investigations.
"There are a lot of police at the site now," the staff member, who asked not to be named because he is not authorized to speak to media, told Reuters by telephone.
He said the plant also makes parts and assemble Apple's iPhone 5.
Calls to the Taiyuan police were not immediately answered, while an official at the plant declined to comment when reached by telephone.
(Additional reporting by Sally Huang in Beijing; Editing by Jonathan Standing and Ken Wills)