Four people have been arrested in Hungary, after more than 70 decomposing bodies were found in an abandoned truck.

The discovery was made in Austria, but the truck had Hungarian plates.

Border officials said the dead migrants were most likely to have come from Syria.

"Among these 71 people, there were 59 men, eight women and four children including a young girl one or two years old and three boys aged eight, nine or 10," police spokesman Hans Peter Doskozil told a news conference on Friday.

He said the time and cause of death still had to be determined but there was a "certain probability" they had suffocated.