More than 20 people died and hundreds were made homeless as the worst flooding to hit Mongolia in decades wreaked havoc on the landlocked nation, an international aid group said Monday.

Beijing-based International Red Cross spokesman Francis Markus told AFP 23 people had been confirmed killed, citing figures provided by Mongolia's Red Cross Society.

The full damage assessment from the rain storms that struck the capital, Ulan Bator, and the nation's western Gobi-Altai province last week, is still being compiled, Markus said.

However he said nearly 2,000 households had been affected, with 124 homes destroyed.

Mongolia's Montsame news agency put the death toll at 24.

Markus said the Mongolian Red Cross had described the flooding as the worst to hit the sparsely populated nation since 1966.

The Red Cross has launched a national appeal calling for donations to meet the crisis. It has been distributing clean water, tents, clothing and mattresses to those areas hardest hit by the flooding, Markus said.