JOHANNESBURG (AP) — Hundreds are dead, many more missing and thousands at risk from massive flooding in Mozambique, Malawi and Zimbabwe caused by Cyclone Idai and persistent rains.

International aid agencies and government officials are scrambling Tuesday to rescue families trapped by the floodwaters from rivers that have burst their banks and are still rising.

Mozambique's President Filipe Nyusi said the death toll could go as high as 1,000 from the cyclone and flooding. Although emergency workers caution they do not know if the fatalities will reach that estimate, they say this is the most destructive flooding in 20 years.

Hardest hit by the cyclone is Mozambique's Beira port, a city of 500,000, where thousands of homes have been destroyed. Flooding waters have inundated large areas of rural Mozambique and its neighboring countries.