Zimbabwe's President Robert Mugabe on Friday declared a "state of disaster" in many rural areas hit by a severe drought, with more than a quarter of the population facing food shortages.

A regional drought worsened by the El Nino weather phenomenon has affected South Africa, Malawi and Zambia as well as Zimbabwe, leaving tens of thousands of cattle dead, dams depleted and crops written off.

Formerly known as the breadbasket of Africa, Zimbabwe has suffered perennial shortages in recent years and has relied on importing grain from neighbouring countries to meet its needs.

"Initial indications were that 1.5 million people were food insecure with all the 60 rural districts being affected," Public Works Minister Saviour Kasukuwere said in a statement.

"Overall, the food insecure population has since risen to 2.44 million -- 26 percent of the population.

"(With) the continued threat of the El Nino-induced drought, his excellency the president has declared a state of disaster in regard to severely affected areas."

Mugabe has blamed low farm yields on erratic rains due to climate change, as well as sanctions imposed by Western countries over the government’s tainted human rights record.

Critics say the food shortages have been partially caused by the president's land reforms enacted since 2000 when the government oversaw the often violent eviction of white farmers.

Many farms are underutilised, and the government has vowed to hold an audit to ensure agriculture land is put into production.

'Bring us food'

"The rains came too late to save the crops. Most of the maize wilted," Enos Janhi, a farmer in Masvingo, one of the worst affected districts, told AFP by telephone.

Farmers are driving their cattle into the fields to graze on the drying stalks. The government must act urgently to bring us food."

Kasukuwere said at least 16,500 cattle have died in Zimbabwe, while as much as 75 percent of crops have been abandoned in the worst-hit areas.

The minister said the Zimbabwean government would take measures to minimise the impact of the drought on both humans and livestock.

But he gave few details, and the country has scarce resources to tackle the food shortages due to years of international isolation and its stagnant economy.

"The April (2015) harvest in Zimbabwe was 50 percent lower than the previous year," said David Orr, spokesman for the UN's World Food Programme (WFP).

"With the drought continuing, it looks like the lean season is going to continue beyond the harvest time this year.

"The number of food insecure people is likely to rise and continue rising."

'No money'

Last month the WFP said 14 million people across southern Africa faced going hungry due to the prolonged drought, with the cost of maize -- the regional staple -- in Malawi 73 percent higher than average.

"People have no money in their pockets -- a situation exacerbated by food shortages," Morgan Tsvangirai, leader of the opposition Movement for Democratic Change (MDC) told a news conference in Harare.

"We are facing a very serious national crisis."

South Africa has recorded its worst drought since records began more than a century ago, and will have to import half its average maize crop.

Last year was the hottest worldwide in modern times, according to the US National Oceanic and Atmospheric Administration.