BELGRADE, Serbia (AP) — The Latest on Europe's migration crisis (all times local):

1:25 p.m.

A leading French humanitarian organization says the number of minors alone in a makeshift camp in Calais has increased by 151 percent to 861 — with the youngest 10 years old.

France Terre d'Asile says it spent three days last week counting kids alone in the camp in northern France and the figure had soared since a May count of 343.

It concurred with other aid groups which put the overall camp population at a record of around 9,000.

The Calais region prefecture says that since March, 55 children have been able to join families in Britain — the dream of most Calais migrants.

The figures were released as British Home Secretary Amber Rudd visits her French counterpart, with Calais likely on the agenda.

1:15 p.m.

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.