The travel warning came after Vietnamese civil society groups today called for renewed demonstrations against China in several cities.
But Vietnamese authorities -- which have occasionally allowed demonstrations to vent anger at the country's giant neighbour -- warned they would "resolutely" prevent any further outbursts.
China's positioning of an oil rig in waters also claimed by Vietnam has ignited long-simmering enmity between two communist neighbours, which have fought territorial skirmishes in past decades, with protests erupting in major cities in recent days and enraged mobs torching foreign-owned factories.
"The Foreign Ministry advises Chinese nationals temporarily not to travel to Vietnam. (It also advises) Chinese citizens and structures in Vietnam to increase their risk-awareness, to strengthen their security prevention measures, and to avoid leaving (their premises)."
Hong Kong also upped its travel advisory today, warning its residents avoid "non-essential travel" to Vietnam.
Earlier today, China's state-run news agency Xinhua reported that security chief Guo Shengkun had spoken to his Vietnamese counterpart and urged the authorities there to quell the violence. Xinhua also said commerce minister Gao Hucheng had called on officials to "bring relevant issues under control".
However, it urged participants to remain peaceful following the chaos Tuesday and Wednesday.
"Those violent actions created a bad image for patriotic demonstrations and the people of Vietnam; therefore, they must be stopped," said a statement issued on social media late yesterday.