Mogadishu, Somalia, is the front lines of the Horn of Africa famine.

It's a capital city of makeshift camps filled with emaciated parents and their malnourished children, according to Cassandra Nelson, a veteran Mercy Corps aid worker who recently spent three days there.

"I have never ever seen so many people so close to death," Nelson said in a Wednesday telephone interview with The Seattle Times from Kenya. "Kids are definitely starving. There is no doubt. "

Mercy Corps, a Portland-based international aid organization with an office in Seattle, is part of an expanding international relief effort under way in Mogadishu in the aftermath of the withdrawal of rebel fighters from their bases in the city.

The United Nations estimate that some 640,000 children in Somalia are acutely malnourished. The effects of the Horn of Africa drought have been compounded by armed conflict that hampered aid shipments.

Nelson said that about 1.5 million people have been displaced in southern Somalia, with about 500,00 now in Mogadishu. Families find refuge in stick shelters covered by blankets, and many don't have any ready access to water.

Disease is another threat. In the Mogadishu area, a cholera epidemic has intensified, with triple the caseload of a year earlier, according to Nelson.

While the capital's airport is now open, Nelson said the amount of aid arriving in the city is still only a sliver of what is needed, and that more and more families are expected to arrive in Mogadishu in the weeks ahead.

"I met people who were walking to the camps, deliver babies, and within hours after that started walking again," Nelson said. "Generous farmers were offering handouts along the way, but there was not enough food."

Mercy Corps had a school-building program in Mogadishu until the fall. This month it reopened aid efforts in the city. The organization has Somali staff, but it has limited the presence of foreign aid workers due to security concerns.

During her recent stay, Nelson said, every move about town was carefully planned. "We are trying to keep a low profile," she said.

Hal Bernton: 206-464-2581 or hbernton@seattletimes.com

Information in this article, originally published Aug. 17, 2011, was corrected Aug. 18, 2011. A previous version of this story was unclear in saying the number of displaced persons now in Mogadishu.