Austrian police discovered three children in critical condition in a truck carrying 26 migrants, BBC News reported Saturday. They arrested the truck's Romanian driver after a chase. The migrants are believed to be from Afghanistan, Bangladesh and Syria.

A police representative told the news agency the children, believed to be about 5 or 6 years, were almost unconscious and severely dehydrated when found. However, officials said Saturday that their lives were no longer in danger.

Meanwhile, four men suspected of involvement in the criminal case centered on the remains of 71 migrants discovered in a truck found abandoned in Austria this week appeared in a court in Hungary Saturday. Three Bulgarians and one Afghan face charges of aggravated human smuggling, BBC News reported.

Under Hungarian law, authorities can hold suspects in custody for as long as 72 hours without charging them. However, the prosecutor in this case has requested that the period be prolonged because of the seriousness of the purported crimes, BBC News said.

Austrian officials said the dead -- 59 men, eight women and four children -- had most likely suffocated inside the abandoned truck. Police discovered it Thursday when it was parked on the side of an Austrian freeway close to the Hungarian border. Officials examined the vehicle after liquid was seen below it, later finding the 71 bodies.

austria refugee memorial In memory of the 71 people who died in a truck found in Austria Thursday, migrants attend a candlelight ceremony at a railway station in Budapest, Hungary, Aug. 28, 2015. Photo: Reuters/Laszlo Balogh

The same day the truck was discovered in Austria, a boat filled with hundreds of migrants sank in the Mediterranean Sea close to the Libyan town of Zuwara, Reuters reported. Friday, 82 of them were reported dead, with about 100 missing and 198 rescued.

These cases have brought renewed urgency to the issues surrounding migrants and refugees. According to the New York Times, the European Union has no standard for granting asylum.

“For the first time in its history, the EU is facing a massive influx of refugees from outside the region, and the EU asylum and immigration framework is poorly adapted for it,” Alexander Betts, director of the Refugee Studies Center at Oxford University, told the Times.

Meanwhile, United Nations Secretary-General Ban Ki-moon responded to word of the latest deaths of migrants seeking shelter by saying Friday: “This is a human tragedy that requires a determined collective political response. It is a crisis of solidarity, not a crisis of numbers.”

At least 2,500 have died this year while attempting to seek refuge in Europe, according to the Office of the U.N. High Commissioner for Refugees.