A Chinese man who was being repatriated from Vietnam along with 15 other migrants seized a gun from a border guard on Friday, triggering a gunfight and standoff in which five Chinese nationals and two Vietnamese guards died, the Vietnamese government said.

Authorities detained the 16 Chinese - 10 men, four women and two children - after they entered the country in Quang Ninh province, the regional government said in a statement.

As guards checked their papers in a room at the Bac Phong Sinh border crossing, one of the Chinese grabbed an automatic weapon from a guard and began firing, the statement said. A standoff ensued, with some of the men holed up in an office, it said.

Vietnamese and Chinese authorities urged the people to surrender, but they refused. Some of the victims jumped to their death from office windows, the statement said, and others were injured.

In total two Vietnamese border guards and five Chinese migrants were killed, according to the statement.

It wasn't clear whether women or children were among the fatalities.

Quang Ninh is opposite the Guangxi Zhuang autonomous region. Many Chinese traders and tourists enter Vietnam through the region.