At least 68 people have been killed and nearly 500,000 displaced by flooding in the west African nation of Niger since July amid heavy rains, the government said in a new toll on Wednesday.

A report from the cabinet of Prime Minister Brigi Rafini said "68 people have lost their lives" in the country's eight regions and 70,353 households, or more than 485,000 people, have been displaced.

In late August, the government said at least 52 people had been killed and nearly 400,000 displaced by flooding since mid-July. Most incidents occurred in the southeastern region of Maradi and in the capital as the Niger River overflowed.

Most of the displaced have been rehoused in schools, mosques and public buildings. Thousands of houses, schools, health centres and mosques have been destroyed by the rising waters.

The government signalled a surge in malaria and cholera in most of the affected areas.

Niamey estimated that the displaced need some 6,000 tonnes of grain.

At Niger's request, a French emergency preparedness team arrived September 2 in Niamey to evaluate how well the local infrastructure and systems for evacuating flood waters were standing up.

The French embassy in Niamey also said the team will evaluate the response capacities and needs of Niger's emergency preparedness personnel.

The floods come as Niger has been hit for several months by food shortages affecting around six million inhabitants.

The floods caused by the rise of the Niger River have also affected neighbouring Benin where four people have already died.