Schoolchildren were among those killed by landslides and flooding in Zimbabwe as the death toll from tropical cyclone Idai rose to at least 157.

The pair of boarders were asleep when a rock fall hit the dining hall and dormitory at St Charles Lwanga school in the eastern province of Manicaland, according to officials in the southern African country.

Cyclone Idai has affected more than 1.5 million people across southern Africa since it hit land in Mozambique last week.

At least 126 people have died in Mozambique and Malawi and another 31 have died in Zimbabwe. Hundreds more are missing or have been left homeless by the disaster.

Both Zimbabwe's president Emmerson Mnangagwa and Mozambique's leader Filipe Nyusi cut short their trips to the United Arab Emirates and Eswatini respectively after being criticised for failing to deal with the crisis.

Mr Mnangagwa declared a state of emergency in the disaster-hit areas and tweeted his "thoughts and prayers" for the victims of the storm.

He added: "Rescue operations are underway and we are grateful for the bravery of the men and women of the Zimbabwean armed forces who, along with our local and international partners, are participating in the urgent rescue efforts."

The major coastal city of Beira, Mozambiqe, was hardest hit, with more than 500,000 residents left stranded in by floods caused by heavy rain and winds of up to 105mph.

The airport was closed, many homes were destroyed and images on social media and local television showed billboards and rooftops blown off, trees snapped and power lines brought down in the streets.

South Africa has also experienced power cuts during the storm because to its reliance on imported electricity from Mozambique, according to reports.

United Nations agencies and the Red Cross are helping with rescue efforts that include delivering food supplies and medicines by helicopter.

The Zimbabwe Red Cross Society appealed on Facebook for help with supplies of clothing, shelter and blankets, along with medical supplies and food.

"We are deeply saddened by the loss of lives and displacements as a result of the Cyclone which has rendered many homeless," the humanitarian organisation said in a statement. "Together we will make a difference. Let us join hands and make a difference as there is never too small an effort in humanitarian work."

Additional reporting by Associated Press