'Making cash from blood': Protesters detained after Ukraine clashes

At least seven protestors were detained as clashes erupted Sunday between Ukrainian police and ultra-nationalists backing a rail blockade in Kiev.

An activist throws a smoke grenade toward riot police during a protest rally in front of the President's Office in Kiev. Source: AP

The violence broke out after more than 1,000 demonstrators gathered to back the blockade between the coal-producing separatist east and the rest of Ukraine, which Kiev has warned could cause nationwide power cuts and job losses.

Those detained included the leader of the Organisation of Ukrainian Nationalists Mykola Kokhanivskyi. Most of those held were injured, a few with head wounds and one with an injured leg, said the AFP journalist near the presidential offices.

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," Kokhanivskiy, commander of his group's volunteer battalion, had told the crowd before the clashes.

The protesters had been 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.

Riot police block the approach to the President's Office at a protest rally in Kiev, Ukraine. Source: AP

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 before the clashes.

"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.