A group of people from Bangladesh, Nigeria and Syria sustained injuries after a van they were driving in overturned and crashed into a field on Tuesday morning, close to a small southern city of Leskovac. Of the 40 people injured in the accident, 20 were seriously hurt and five remained in a critical condition.

"Five patients have broken spines, legs or arms, or severe abdominal injuries" head of Leskovac General Hospital Nebojsa Dimitrijevic told the Serbian news agency Beta.

"All the doctors, all the services have been enaged. The injured are still arriving to the hospital."

The driver fled the scene and officers are still searching for him, police spokesman Boban Zdravkovic confirmed to the Beta agency.Police were also trying to determine the exact number of people in the van and why it swerved off the road on a straight stretch of highway some 300 kilometers (186 miles) south of Serbian capital Belgrade.

Smuggler's route through Balkans

The migrants entered Serbia from Macedonia, according to a report by Serbian public broadcaster RTS. One of the migrants told the reporters that the group was traveling to Europe to seek asylum.

In recent months, tens of thousands of Kosovo Albanians have also attempted to illegally enter Hungary by going through Serbia, and apply for asylum in western Europe.

Serbia borders three EU countries and is a well-known route for smuggling immigrants, drugs and weapons into western Europe.

dj/rc (AP, AFP, dpa, Beta)