Seventy-five workers at United Company RusAl's North Ural Bauxite Mine in the Sverdlovsk region began a hunger strike Sunday, a union leader said.

Alexander Anisimov, deputy head of the local Independent Miners' Union, said by telephone late Sunday that the miners were staying in the administrative building of the Little Red Riding Hood mine, which is part of the larger RusAl complex.

"We decided to take the step when RusAl said it was ready to increase our salaries 5 percent, or about 800 rubles [$34]," Anisimov said.

The miners had previously asked for a 50 percent increase, saying their wages fell dramatically last year without any explanation from RusAl.

"They again threatened us with fines and dismissals, even though they have signed a paper saying they wouldn't," Anisimov said.

RusAl said it was ready to pay miners more if their productivity increased, because the company had no additional resources to increase wages with the present mine output, Anisimov said.

"We don't believe RusAl doesn't have money to pay us," he said. "Company chairman Oleg Deripaska is the richest man in the country, he has got billions."

A RusAl spokesman confirmed the strike, saying it was an attempt to disrupt negotiations between workers and the company. "We're looking at this small group's protest as an attempt to derail the negotiation process and stop work in the North Ural Bauxite Mine's shafts," he said, Interfax reported.

Almost 100 miners occupied the Little Red Riding Hood mine late last month, agreeing to come to the surface 10 days later, on April 3, after senior RusAl officials arrived to negotiate. RusAl filed a lawsuit against the miners, saying they went on strike illegally. The next court hearing is scheduled for April 22.