Migrants' desperate pleas for help as winter approaches

The authorities in Serbia are warning that the number of migrants entering the country has risen sharply, with more than 20,000 people arriving in the past three days.

They say they are coping at the moment, but there have been delays registering people, and there are fears that with colder weather coming, many migrants and refugees will suffer.

Ed Thomas reports from the border town of Preshevo in Serbia.