Austrian officials revealed Friday after further investigation that there were 71 dead migrants inside the truck that was discovered on a highway in Austria.

The number of dead immigrants inside the truck rose to above 70 on Thursday, reported The Wall Street Journal. Austria's police and interior ministry initially estimated the number to have been between 20 and 50.

Officials confirmed the final count at a news conference, which included 59 men, eight women and four children. One infant was also found among the dead, according to The New York Times.

Based on evidence at the scene, investigators believe that the victims suffocated long before the vehicle was abandoned.

Hans Peter Doskozil, chief of police in the province where the vehicle was found, revealed that Hungarian police detained seven suspects and arrested three of them early Friday. He noted that two of the suspects are Bulgarians, while the third is suspected to be Hungarian, according to Fox News.

"We believe that one perpetrator, a Bulgarian citizen of Lebanese descent, is the current owner of the vehicle," Doskozil said. "Two other suspects who have been detained include a Bulgarian citizen and an individual in possession of a Hungarian identity card, whose nationality has not yet been determined, both believed to be the drivers of the truck."

However, Doskozil believes the three arrested suspects only represent the lowest rank of a much wider Bulgarian-Hungarian human trafficking ring. He noted that due to a Syrian travel document found among the bodies, it's possible that at least some of the victims were fleeing the violence in that nation.