Authorities in the northeast town of Garissa detained the market vendors and recovered 500 bags of beans intended for drought relief that had been repackaged to be sold, government spokesman Alfred Mutua said.

"The government will ensure that no food meant for hungry people is diverted," Mutua said.

"This is an isolated case and the government reacted immediately because it takes the issue of providing food to the hungry seriously," he said, adding that police were moving to dismantle a cartel suspected of stealing food aid.

On Thursday, residents of Garissa, about 300 kilometers (185 miles) northeast of Nairobi, complained to authorities that relief food marked "not for sale" was being sold in local grocery stores and markets.

At least 40 people have died from drought-related malnutrition or associated illness in Kenya since December and President Mwai Kibaki has declared the drought a national emergency.

More than 2.5 million Kenyans, mainly in the northeast, are expected to need food aid to survive by the end of next month because of the drought which has left millions more in imminent danger of starvation across east Africa.

Earlier Friday, the UN World Food Programme warned of an impending "humanitarian catastrophe" in four Horn of Africa nations -- Djibouti, Ethiopia, Kenya and Somalia -- where it said some 5.4 million people were at risk.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.