Sixteen people have been killed when a bus transporting Hungarian students crashed in northern Italy.

The bus was traveling from France to Hungary on Saturday when it crashed.

More than two dozen people were also injured.

The bus was carrying the students home from a school ski trip to France. The vehicle burst into flames when it hit a highway barrier.

Officials said an overpass support column entered into the bus while some people were burnt beyond recognition in the severe incident. The bus was completely torched, leaving only a skeleton of twisted steel.

Local officials in Verona said no other vehicles were involved in the crash and that the cause was still unknown. They said no brake marks were found at the scene, prompting speculations that the driver could have lost control of the vehicle. An official in Hungary's consulate said investigators were looking into the possibility that the driver fell asleep behind the wheel.

Hungarian Foreign Minister Peter Szijjarto said a total of 39 people survived the crash.

One teacher, who reportedly suffered serious burns to his back, managed to save some of the kids.

"The kids told me that the fire started and they escaped from the fire, breaking the windows of the bus," said the teacher, adding, "Some of them managed to escape, but many were left inside."

"One passenger is currently in an induced coma and in life-threatening condition," Szijjarto said.

Students gathered for a vigil outside Szinyei Merse Pal Gimnazium in the Hungarian capital, Budapest. A black flag flew from a flagpole above the school while students lit candles and laid small flowers in memory of the victims.

Italy's president and its foreign minister as well as the German chancellor have issued condolence messages on the incident.