BEIJING, (UPI)Chinese state-media said Thursday about 10 of its nationals are missing after rioters in Vietnam attacked Chinese businesses to protest a contentious oil rig.China National Offshore Oil Co. in early May deployed an oil rig in waters contested by both China and Vietnam. Vietnam says it has historical proof the rig is violating its sovereignty, though China said it’s operating within its territory and urged the Vietnamese government to stop disrupting its oil exploration activities.

Vietnamese protesters attacked Chinese businesses in Vietnam’s central Ha Tinh province. China’s official Xinhua News Agency reported ten Chinese nationals are unaccounted for following Wednesday’s protests.

Vietnamese officials said nearly 600 people were arrested in connection to the riots. Police officials said order “broke down” and all parties to the melee were called on to exercise restraint.

The oil rig’s deployment follows a series of disputes between China and its Asian neighbors over territory in the South China Sea.

U.S. State Department spokeswoman Jen Psaki said Tuesday the behavior from the Chinese undermines regional peace, “though we don’t take a position on the sovereignty over this area.”

Topics: Jen Psaki