The United Nations' top aid official says Somalia's government disagrees with the U.N. about the severity of the humanitarian crisis in the country.

John Holmes, the U.N.'s Undersecretary-General for Humanitarian Affairs, told the U.N. security council on Monday that Somalia's leaders gave far lower estimates than the U.N. of the number of people who fled Mogadishu after April's heavy fighting.

The U.N. says 400,000 people fled the capital, but Holmes says Somali President Abdullahi Yusuf Ahmed and Prime Minister Ali Mohamed Ghedi told him not more than 40,000 were displaced by the fighting. He says the Somali leaders said half of those have returned.

Holmes says most refugees have not returned and that many live in deplorable conditions in the countryside.

Some information for this report was provided by Reuters.