Ukraine ultra-nationalists protest to back rail blockade

More than 1,000 ultra-nationalists staged a protest in Kiev on Sunday to back a blockade between the coal-producing separatist east and the rest of Ukraine that the government has warned could cause nationwide power cuts and job losses.

Ukraine has declared a state of emergency in the energy sector over the railway blockade, which was launched in late January to protest at Kiev trading with Russian-backed rebels in the east.

"We once again warn the authorities who trade coal with the occupied territories, making cash from blood," Mykola Kokhanivskiy, commander of the Organization of Ukrainian Nationalists volunteer batallion, told the crowd.

The protesters were escorted by hundreds of members of the security forces as they marched from Kiev's Independence or Maidan square to the offices of the president.

President Petro Poroshenko has described the blockade as a "destabilising factor" for the war-scarred and cash-strapped former Soviet state.

The pro-Western leader has warned that the coal delivery stoppage would leave parts of Kiev and other cities without heating, and said it could cost 300,000 jobs as factories grind to a halt without power.

But protesters took aim at Poroshenko at Sunday's march.

"Shame on the corrupt government!", "The enemy is within!" they shouted, some hurling firecrackers.

"Poroshenko benefits from this trade, that's why he is against the blockade," said 51-year-old pilot Yevgen.

"He is afraid of his people. Well, for him this is not his people, it's the flock whose fleece he wants to cut for a long time, brazenly and scot-free," he added.

The 34-month conflict in eastern Ukraine has claimed more than 10,000 lives and left Kiev without full control of its vital industrial belt.