Over 500 migrants crossed the border between Serbia and Croatia this morning as hundreds more were held behind temporary fences between the two Balkan territories, as the Croatian authorities attempt to slow down the flow of people into its border.

One of those waiting to cross was Syrian refugee Mohammad al-Imam, a former professional basketball player.

When al-Imam left the Middle East, he was the Under-16s coach of Al-Ittihad, a top level team from Aleppo.

He was travelling with his two daughters and other members of his family.

The former sportsman said he had no other choice but to leave his life behind.

"Every day, every night the bomb is close to my neighbourhood and everything is terrible because we don't have electricity, we don't have water, we don't have gas, we don't have petrol. We don't have anything. We don't have education, we don't have doctors in our country, we don't have anything in Aleppo city, because of that I decided to leave," he added.

Croatia is sending migrants north across its own border with Hungary - which in turn sends them to Austria - but is struggling to keep pace with the influx.