Serbia's defense ministry says three people have been detained for attempting to smuggle 64 migrants from Afghanistan, including a pregnant woman and a baby.

The ministry said Tuesday that a joint police and army patrol near the border with Bulgaria caught the smugglers late Monday as they were transferring the migrants.

It says a group of 34 migrants were packed in a van, while another 30 migrants were about to board two cars. They included mostly men, four women, children and a baby.

Many refugees and migrants fleeing war and poverty have been turning to people smugglers to guide them through the Balkans and on toward the European Union after countries closed their borders in March.

More than 1 million migrants entered Europe in 2015.