The Civil Aviation Authority of Vietnam has ordered airlines not to fly directly over areas involved in armed conflict in the Middle East, local media reported.
News website VnExpress said the agency has also submitted a plan for alternative routes to minimize risks to the Ministry of Transport.
The order came nearly a month after the International Civil Aviation Organization on October warned about possible risks to international civil air traffic in Tehran, Baghdad and Damascus as a result of the armed conflict in Syria.
"Taking into account the armed conflict, which currently takes place in the Syrian Arab Republic, we would like to draw your attention to the possible existence of serious risks to the safety of aircraft engaged in international flights in parts of flight information regions in Baghdad, Damascus and Tehran," Fan Liu, the secretary general of the organization, said in a letter.
On October 31, Kogalymavia Flight 9268, an international chartered passenger flight operated by Russian airline Kogalymavia (branded as Metrojet), crashed in northern Sinai. It departed from Sharm el-Sheikh International Airport, Egypt, en route to Pulkovo Airport, Saint Petersburg, Russia.
The aircraft, an Airbus A321-231, was carrying 217 passengers, mostly Russians, and seven crew members. All of them died.
Investigations into the cause of the crash are ongoing.