A nationwide strike in Nigeria is in its third day Friday after overnight talks between government and union officials broke down.

People stand next to their motor bikes as they await fuel to arrive during a nationwide general strike in Lagos, 21 Jun 2007

Unions have threatened to shut down the country's water and electricity supplies unless the government fully reverses a recent 15 percent increase in fuel prices.

The strike has already shut down most schools, banks, and government offices across the country. Oil production and exports appear to be unaffected, although the unions have threatened to halt those activities as well.

The increase in fuel prices was imposed by former President Olusegun Obasanjo before he left office last month. His successor, Umaru Yar'Adua, has offered to cut the price increase by half.

A top government negotiator, Babagana Kingibe, said Friday that authorities will clamp down on union efforts to block streets and forcibly shut down businesses that want to open. He said that kind of act is against the law and will no longer be tolerated.

Nigeria is one of the world's biggest producers of crude oil, but it is almost completely dependent on imports of refined fuel. The central government has subsidized fuel for many years - a move that impoverished Nigerians have come to depend on as one of the few benefits they receive from Abuja.

Some information for this report was provided by AFP and AP.