He said two major generating stations run by state-owned Tanzania Electrical Supply Co. will stop running next week.

"We can supply reliable power until mid-next week. Power rationing could begin any time this month," Rutanzibwa said.

For the past five months, electricity has been erratic in the commercial capital Dar es Salaam, the roar of generators a daily ordeal for its denizens.

Even two geothermal power stations that contribute a little less than a third of Tanzania's output are having difficulties and have seen their total production fall off.

"This does not help the situation. We have problems in both hydro and thermal power production," Rutanzibwa said.

Tanzania's total generation capacity is 953 megawatts (MW), more than two-thirds of which is hydroelectric.

Tanzania will be hard-pressed to import power from neighbouring Kenya and Uganda, since Kenya's hydropower plants are facing shortages of their own and Uganda does not have enough power for its own needs.

Poor rainfall across much of east Africa and the Horn of Africa over the past year has produced a drought that the United Nations says is putting almost 6 million people at risk of starvation.

Tanzania, a nation of more than 35 million people, was not included in those estimates.