Smugglers who help take migrants from Bulgaria into Serbia are being assisted by Bulgarian police, a migrant has told SkY News.

A correspondent for the British TV channel has talked to a migrant named as Azad Ali, who claims "those people are working with the help of Bulgarian police."

"I saw a policeman who lifted the boot of the car and he saw migrants in the car."

"We were in the mountains for three days and three nights and for two days had no food or water because the smuggler left us in the mountains. My kids nearly froze - their hands got back," he goes on, but adds a taxi driver came later to take them to Belgrade.

EU police from countries including Austria have been deployed to Serbia to help stop the inflow into Europe, Sky News notes.