Hungary struggling to register all migrants

The migrants have to wait in an open field lacking facilities, and are then transported by bus to Roszke, where their processing starts.

Hungary insists that under EU law all new arrivals have to be registered and fingerprinted.

But aid workers say many migrants, who intend to travel on to Austria and Germany, do not want to be processed fearing they will be transported back to Hungary.

On Tuesday afternoon, dozens of migrants broke through police lines and started marching towards Roszke and further onto Budapest, some 170 kilometers away.

The camp in Roszke is able to hold 800 people and cannot cope with the influx. On Monday alone, 2,706 people arrived in Hungary, according to police figures.

Aid workers expect a bigger number to arrive over the weekend.

In the meantime, Hungary's prime minister vowed to speed up the construction of an anti-migrant fence along the Serbian border.

The four-metre high fence is to be completed by the end of October or beginning of November.

Hungary's defence minister resigned late Monday, and it has since emerged that he quit because of the slow pace of the fence's construction.

The PM, Viktor Orban, told an online newspaper that he was convinced "the works in progress have to be sped up", AFP reported.

A razor-wire barrier along the 175-kilometre border was completed on August 29, but failed to prevent migrants from climbing over.

The contentious frontier has become a major crossing point into the European Union, with around 160,000 entering Hungary so far this year.

The European Commission said on Tuesday it has allocated €4 million in emergency assistance to Hungary.

A request for €8 million was made by the country in mid-August. The money is to be used to improve the infrastructure of existing reception facilities as well as to develop new ones.