Namibia's president declared a state of emergency Tuesday in the north after heavy flooding that has killed 92 since January and displaced thousands, as he appealed for international aid.

"It is with a heavy heart that I declare an emergency for the north-central and north-eastern parts of Namibia," President Hifikepunye Pohamba told reporters at a special briefing.

Pohamba said 92 people have drowned since January and 218 schools closed, leaving 100,000 children unable to attend classes.

"Crop fields are submerged in water, and I send out an urgent appeal to the international community for assistance ...as the current flood is worse than a year ago and could be one of the worst in recent memory," he said.

Last March the government also declared a state of emergency and pumped in 200 million Namibian dollars (20 million dollars/15 million euros) into the disaster areas for emergency food, transport and repairs.

Pohamba said the Zambezi River had swelled to 7.10 metres (about five feet) against a peak of 5.37 metres during last year's floods.

He said 729 households had been affected and 89 of them relocated.

Severe flood has also hit just across the border in Angola, where the Red Cross says 19 people have died this month in the disaster.