KIEV -- Ukraine coal miners widened their strike to 57 pits Thursday on the fourth day of a protest demanding unpaid wages and an end to cheap coal imports from neighboring Russia, union officials said.
"The government must understand that the situation is serious," said Mykhaylo Volynets, head of the Ukrainian Independent Miners Trade Union. "Work has now stopped at 57 pits."
Volynets said 130,000 coal miners had now stopped work, making it the biggest halt in months. Miners often halt work at the former Soviet republic's 260 pits.
Union officials say wage debts to miners total about 2.24 billion hryvnias ($1.1 billion) and have been delayed by up to 10 months.
Volynets said Ukrainian Prime Minister Valery Pustovoitenko and coal ministry officials planned to meet strike leaders.
On Wednesday, Volynets said miners planned a protest march through the capital, Kiev. About 3,000 foreign investors are gathering in the city at the weekend for the European Bank for Reconstruction and Development's annual general meeting.
Meanwhile, Ukraine's emergencies ministry said another two miners were killed in accidents Wednesday, bringing mine deaths to six so far this week.
Trade unions and coal mining companies say large debts from consumers and slow reforms are to blame for poor safety. Last month, a methane gas explosion killed 63 miners in the eastern city of Donetsk.
Officials have said 163 Ukrainian coal miners have died since the start of the year.