Violence has once again broken out in a Greek refugee camp with blood-spattered migrants seen battering one another with rocks in an apparent fight over a loaf of bread.

Last month armed police officers fired tear gas at crowds of people in the village of Idomeni on the Greek-Macedonian border, after a group of asylum seekers busted through a razor-wire fence.

Some 13,000 people are living in the refugee camp - and there are fears of more violence if the 'Balkan route' from Greece through to Europe is closed.

Fight: Violence has once again broken out in a Greek refugee camp with blood-spattered migrants seen battering one another with rocks in an apparent fight over a loaf of bread

The fight comes just over a week after armed police officers fired tear gas at crowds of people in the village of Idomeni on the Greek-Macedonian border, after a group of asylum seekers busted through a razor-wire fence

More than 985,000 have travelled along it since the start of last year.

News of the violence came as it emerged Turkey is seeking an extra three billion euros in aid under a deal with the EU to curb the flow of migrants to the continent.

The country's Prime Minister Ahmet Davutoglu told 28 EU leaders at an emergency summit that Ankara was willing to take back all migrants who enter Europe from Turkey after a set date, as well as those intercepted in its territorial waters.

Meanwhile, dozens of men, women and children held a sit-down protest on the railway tracks running past the Idomeni refugee camp, calling on European leaders meeting in Brussels to open the borders.

Macedonian authorities have set up a 19-mile barbed wire boundary, with parallel lines of 8ft fencing keeping thousands of migrants trapped in Greece.

Injured: Some 13,000 people are living in the refugee camp - and there are fears of more violence if the 'Balkan route' from Greece through to Europe is closed. One of the migrants involved in the fight is pictured bloodied

Brawl: News of the violence came as it emerged Turkey is seeking an extra three billion euros in aid under a deal with the EU to curb the flow of migrants to the continent. Two migrants are pictured fighting at the camp

Argument: A migrant waiting to cross the Greek-Macedonian border is seen hurling a rock at another man

Only a narrow passage has been left in a bid to control migration flow, with officials growing increasingly stringent.

Frustrated refugees in Idomeni have occasionally blocked freight trains from passing down the tracks for hours.

But Monday's protest was more symbolic in nature as no train was passing and a Greek television station had also set up a marquee with a live camera position on the track beside the protesters.

As night fell, the protesters braved rainfall, holding up banners made of sheets and chanting 'Germany, Germany' and 'Mama Merkel,' referring to German Chancellor Angela Merkel whom they see as sympathetic to their plight.

About 13,000-14,000 people are stranded in Idomeni.

In exchange for stopping the influx, Davutoglu demanded a doubling of EU funding through 2018 to help Syrian refugees stay in Turkey and a commitment to take in one Syrian refugee directly from Turkey for each one returned from Greece's Aegean islands, according to a draft document seen by Reuters.

Throwing punches: Frustrated refugees in Idomeni have occasionally blocked freight trains from passing down the tracks for hours. Several are seen trying to break up a fight at a camp in the Greek village

A migrant waiting to cross the Greek-Macedonian border is said to have got into a fight over a loaf of bread

He also sought to bring forward visa liberalisation for Turks to June from late this year and to open more negotiating chapters in Turkey's long-stalled EU accession process.

An emergency EU-Turkey summit, originally due to last half a day, was extended to give Davutoglu a chance to present the new ideas that went beyond Ankara's commitments so far.

European Commission President Jean-Claude Juncker's chief of staff said on Twitter that good progress had been made in the difficult talks and 'a breakthrough during this night is possible'.

Meanwhile, David Cameron today declared there is 'no prospect' of Britain joining a common European Union asylum system and stressed that the UK keeps its own borders to prevent migrants getting into the country.