BRUZGI, BELARUS (NYTIMES) - He has spent 28 nights, each colder than the one before, choking on campfire smoke and despair on Europe's doorstep. He made it across the razor wire into Poland three times, only to be grabbed in the forest and forced back into Belarus. His visa for Belarus expired 12 days ago, leaving him at the mercy of a repressive police state.

On Tuesday (Nov 16), Mr Rawand Akram, a 23-year-old Kurd from Iraq, snapped.

He and hundreds of other desperate and increasingly angry migrants, marooned at the border - and egged on, he said, by Belarusian security officials - stampeded towards a frontier checkpoint, hurling stones and debris at Polish security forces massed just a few yards away.

What began around noon as just another attempt to breach the border fence spiralled into a dangerous melee, and Polish officers responded with volleys from water cannons and blasts of tear gas.

"I am angry. Everyone is angry. This is the last thing we could do. There is no other solution if we ever want to get to Europe," Mr Akram said.

Hours later, Belarus border guards suddenly began moving hundreds of migrants from their frozen encampment to the shelter of a nearby warehouse. It was not immediately clear what plans the authorities had for those they were moving, but many feared that the relocation was a prelude to deportation.

Tuesday's clash, the worst in a months-long impasse on the European Union's eastern flank, underscored the perils of a standoff between Belarus, a close ally of Russia, and Poland, a member of the North Atlantic Treaty Organisation and the EU. At least 11 people have died at the border in recent weeks.

Mr Akram said Belarusian security officers had instigated the melee by telling migrants stranded in a fetid, frozen encampment just yards from Poland that Warsaw's hard-line nationalist government would never let them enter unless forced to do so.

He also blamed Poland for putting its determination to resist pressure from Belarus' authoritarian leader Alexander Lukashenko ahead of the lives of desperate people.

EU officials have called the crisis a hybrid war engineered by Mr Lukashenko to punish Poland.