North Korea has confirmed to international aid agencies that 133 people have been killed and an additional 395 remain missing. More than 35,500 houses and 8,700 schools and other buildings were damaged, as well as almost 40,000 acres of arable land, they said.

On Wednesday, Central TV, the state-run broadcaster, said that the latest floods were among the worst in decades and left 68,900 people without shelter. It also reported extensive damage to bridges, roads and rail lines. It reported what it described as a detailed, coordinated nationwide effort by various state agencies to help the victims under instructions from the country’s leader, Kim Jong-un.

The number of people affected is likely to increase, as some of the flooded villages have not yet been reached, the World Food Program said.

Darlene Tymo, the program’s relief coordinator for North Korea, said that the floods came just before the harvest period, when the crops were still in the ground.

The World Food Program said it supplied emergency food by diverting fortified food stocks from local factories that it has been running to feed children and pregnant and nursing mothers. It said it required $1.2 million to replenish the stocks for the children and women. Over all, it said it needed $21 million until next August to help people in North Korea, where it said more than 70 percent of the population suffer food shortages.

Despite recent efforts to plant trees, many of the hills in North Korea, a mountainous country, remain bare after decades of cutting trees for firewood and making room for terraced farm patches. That makes North Korea particularly vulnerable to frequent floods and droughts.

A series of floods and droughts led to a famine in the mid- and late 1990s, leading the isolated country to issue a rare appeal for international help. By some estimates, more than a million people died.

The North’s food situation has improved in recent years. But international aid groups have called each year for donations to help feed the poor. Countries like South Korea have become increasingly reluctant to provide the generous aid they used to give, accusing the North of squandering its resources on its nuclear weapons program.