Johannesburg, Oct 5 (IANS): Thousands of workers began a strike in the coal sector on Sunday after their demand for higher pay was rejected by employers.

The National Union of Mineworkers (NUM), which organised the strike, said more than 30,000 workers were taking part in the strike which is expected to paralyze the coal sector, Xinhua news agency reported.

The union called the strike after wage talks were deadlock due to employers' rejection of a demand for a pay hike of 1,000 rand (about $73) for workers in the lowest paid category. The employers were offering 300 rand (about $22) instead.

The strike came as the country is facing a severe shortage of electricity, resulting in load shedding over the past few months.

South Africa relies heavily on coal for electricity. Power stations have been forking out billions of rand to buy diesel to keep the lights on due to the shortage of coal. The strike is expected to make things worse.

The union's spokesperson Nelson Ratshoshi said they were well aware of the impact of the strike.

"It will affect investors because any strike will affects investors. Even now the country is facing a serious economic challenge," said Ratshoshi.

Coal mining in South Africa produces enough coal to account for 94 percent of its energy production, according to the Chamber of Mines.

South Africa is one of the world's top five coal exporters and the industry directly employs close to 90,000 people.