Floods that devastated North Korea last month are turning out to be worse than initially feared, with more than 100,000 people left homeless, according to aid workers who visited the area last week.

That puts Pyongyang in the inconvenient position of having to turn to the international community for help — at the same time North Korea is facing global condemnation after its nuclear test last week.

“The effects of this flooding will be even more dramatic and devastating than initially thought,” said Chris Staines, the head of the Pyongyang office of the International Federation of Red Cross and Red Crescent Societies. “The people there are in a very desperate situation.”

Staines was part of a group of 22 international and local staffers from 13 aid agencies stationed in Pyongyang who last week visited the northern city of Hoeryong, across the Tumen River from China.

Floods ripped through the area Aug. 30 as Typhoon Lionrock lashed northeast Asia. North Korean authorities at first estimated that 44,000 people had been displaced between Onsong, in the north, and Musan, a major mining center 100 miles downriver.

The Washington Post's Anna Fifield reports on North Korea's fifth nuclear test and what it means for the region and one of Kim Jong Un's few allies, China. (Jason Aldag,Anna Fifield/The Washington Post)

The North Korean government has confirmed that 133 people have been killed and 395 are missing as a result of the floods, the U.N. Office for the Coordination of Humanitarian Affairs said Sunday.

At least 140,000 people are in urgent need of assistance, the OCHA said in a statement, including an estimated 100,000 people who have been displaced. Water supplies to about 600,000 people have been cut.

“My impression was that this was a much worse disaster than the statistics indicate,” Staines said by Skype from Pyongyang. “The damage is very extensive, and there is clear evidence that the floodwaters were not only very high — you can see the watermarks above the window frames — but also moving very rapidly in some places.”

Authorities took the aid workers, some of whom represented U.N. agencies, to destroyed medical clinics and to a water pumping station near Hoeryong that was wiped out, leaving 50,000 people without water. Kitchen gardens and household livestock — chickens, ducks, pigs — also were washed away, Staines said.

“These households have clearly lost everything,” he said.

In some areas, communication links remain cut and the roads are still impassable.

North Korean authorities initially asked aid agencies to help with relief efforts using their existing budgets and supplies. But now officials plan to launch international appeals for donations.

Their timing could hardly be worse. On Friday, Kim Jong Un ordered North Korea’s fifth nuclear test and its largest yet, triggering international calls for more sanctions to punish the regime.

South Korea’s Defense Ministry warned Monday that Pyongyang could order another nuclear test at any time. The South’s Yonhap News Agency reported, citing unnamed government sources, that the North has completed preparations for a sixth test.

With so many other crises around the world competing for donations, agencies operating in North Korea — which include the United Nations’ World Food Program and UNICEF, as well as a handful of European organizations — have confronted difficulty raising money for their projects for several years and have had to scale back operations.

North Korea said the flooding was caused by the “strongest storm and heaviest downpour” since World War II. The government redirected people involved in a “200-day campaign” intended to increase production to instead help with the relief efforts.

Soldiers were sent to the disaster area Saturday, according to the official Korean Central News Agency. Workers on Ryomyong Street, an ambitious development in Pyongyang that is trumpeted in the state media on an almost daily basis, also were dispatched.

Tens of thousands of houses and public buildings collapsed, while railways and roads, along with factories and crops, were destroyed or submerged, KCNA reported.

North Korea is particularly prone to flooding because of deforestation — a result of people cutting down trees to fuel fires in their homes — and a tendency to turn every inch of arable land over to crops. Making matters worse, houses, particularly in the downtrodden northern areas, are often made of substandard, locally produced bricks.

Staines asked donor nations to remember that the flood has hurt regular people in North Korea.

“In the communities we visited, we were allowed to meet with local people, and we could see their spirit and their energy and their support for each other,” he said. “These are people who are doing the best they can. They’re just normal, everyday people.”