At least 24 people have been killed and dozens are missing as tropical cyclone Idai hit eastern parts of Zimbabwe after lashing neighbouring Mozambique, the government said on Saturday. Most of the deaths were in Chimanimani East, Zimbabwe's information ministry announced on Twitter, saying at least 40 other people had been injured. Two of the victims were students who died when a boulder hit their school, causing the wall of the dining room to collapse on top of them, the state-run Zimbabwe Broadcasting Corporation said. The boarding school has been shut with the students waiting to be airlifted to safety by the army, which is leading rescue operations. Others who fled their homes were "marooned" on top of a mountain waiting to be rescued, but strong winds were hampering helicopter flights, the ministry said. The storm damaged many houses and washed away bridges in the eastern Manicaland province which borders Mozambique, with a lawmaker telling AFP thousands of people have been affected by power cuts and flooding. "The information we have so far is that over 100 people are missing," said Joshua Sacco, an MP in Chimanimani district. "At least 25 houses were swept away following a mudslide at Ngangu township in Chimanimani urban. There were people inside," he told AFP, saying they were listed as missing. The opposition Movement for Democratic Change demanded immediate help for the storm-hit east, warning that a "serious humanitarian crisis" was unfolding there. "We need state intervention on a massive scale to avoid biblical disaster," wrote MDC spokesman Jacob Mafume on Twitter. Tropical cyclone Idai battered central Mozambique on Friday killing at least 21 people and cutting off more than half a million people in the port city of Beira. Even before the cyclone made landfall on Friday, heavy rains earlier in the week had already claimed 66 lives and displaced 17,000 people in Mozambique, local officials said. They had also affected neighbouring Malawi, where 56 people died and nearly a million others were affected, the government said. As the cyclone hit, Mozambique's President Filipe Nyusi appealed for emergency assistance for the victims before leaving for eSwatini. "We have compatriots suffering without hope and we have to restore hope," Mr Nyusi said on Friday as he set off on a three-day state visit to the kingdom that was previously known as Swaziland. As the cyclone approached, the Red Cross sent out more than 200 volunteers to areas most likely to be affected. "The situation is dire but we don't know the exact particulars," said Jamie LeSueur, the Red Cross's roving emergency operations manager for Africa, who was making the 1,200-kilometre trip from Maputo to Beira by road after flights were cancelled and the airport closed. Describing it as a "difficult emergency" to tackle, he told AFP said it would require "the full force of the humanitarian community behind the government of Mozambique to respond to rapidly." Beira's international airport was closed after the cyclone made landfall, damaging the air traffic control tower, the navigation systems and the runways. "Some runway lights were damaged, the navigation system is damaged, the control tower antennas and the control tower itself are all damaged," an official at the National Institute of Disaster Management said on Friday "The runway is full of obstacles and parked aircraft are damaged." The storm also affected power supplies to neighbouring South Africa which imports electricity from Mozambique to supplement its own production. South Africa's power utility company Eskom on Saturday introduced severe electricity rationing "due to the loss of additional capacity, which includes a reduction in imports from Mozambique".