Croatia's interior minister has warned that the country is overwhelmed with more than 7,000 refugees pouring in from Serbia and it cannot accept any more people as thousands of migrants have broken through police lines following clashes.

Chaotic scenes were recorded at Croatia's Tovarnik railway station after a group of stranded and exhausted refugees started to march towards the capital, Zagreb. About 500 people were stopped by police as they tried to break through the barrier. At some point, police gave up and thousands started running or walking deeper into Croatia.

After the cordon was breached, some men and women collapsed as they were shoved through the crush or because of the heat. Extra buses dispatched by the Croatia's government have been unable to cope with the numbers.

Migrants also broke through police lines in Batina, a border town with Serbia, with footage from Sky News showing hundreds of people crossing the border.

Croatia's interior minister Ranko Ostojic suggested that the country will not create a corridor for refugees to pass through and they will have to claim asylum there, or be considered illegal migrants. A total of 7,300 people have arrived in Croatia in the past couple of days, which is almost three times the number of last year.

The development came as the European Council president Donald Tusk summoned EU leaders to an extraordinary summit on Wednesday 23 September to discuss migration and a scheme to redistribute 120,000 asylum seekers across the continent.