CAIRO — A year ago, a cease-fire agreement signed in Stockholm provided a blueprint for what many hoped would lead Yemen out of its devastating war and humanitarian crisis. It centered on disarming the warring sides in the strategic port city of Hodeida.

A year later, Hodeida remains the most dangerous place for civilians in Yemen, 15 aid organizations said in a statement Thursday.

This year — the conflict’s fifth — 799 civilians have been killed in the city and its surroundings despite the cease-fire agreement, the aid groups said. That represents a quarter of all civilians killed or wounded across the Middle East’s poorest country, and the highest toll of any single area there.

Hodeida is also one of the two deadliest places for children in Yemen, according to Save the Children. Between January and October this year, 33 children were killed or injured every month in Hodeida and in the southwestern city of Taiz. Nearly half of all Yemeni children who have been killed in the conflict have died in these two cities, the charity said.

To be sure, the aid groups said, there has been a drop in civilian deaths in the conflict — 1,008 civilians killed so far this year, compared with 2,049 last year. But Yemen remains the world’s worst humanitarian crisis, the groups said.

More than 390,000 Yemenis were forced to flee their homes this year, according to the aid groups. Half of all the displaced this year were in Hodeida province and two others.

Aid organizations have been hampered in their efforts by the fighting and restrictions imposed by authorities and armed groups. Yemen’s infrastructure also has been hit hard, with hospitals, schools and water systems damaged or destroyed by airstrikes or shelling.

“As aid agencies working in Yemen, we are outraged that after almost five years, Yemenis continue to suffer from an incalculable humanitarian crisis fueled by conflict,” the aid agencies, including Care and Oxfam, said in their statement.

“Civilians continue to bear the brunt of the violence. Houses, farms, markets and health facilities are damaged and destroyed worsening an already dire humanitarian situation.”

The war pits a coalition of regional Sunni Muslim powers, led by Saudi Arabia and the United Arab Emirates, against Shiite rebels who are aligned with Iran. The U.S.-backed coalition is ostensibly seeking to restore Yemen’s government, which was ousted by the rebels, who are known as Houthis.

The humanitarian crisis resulting from the conflict has left at least 10­ million Yemenis facing starvation and 7 million others malnourished. More than 100,000 have died since 2015, including more than 12,000 civilians in direct attacks, according to the Armed Conflict Location and Event Data Project, a nonprofit organization that monitors war casualties.

Some of the conflict’s most violent spasms unfolded in Hodeida, a vital gateway for food, medicine and other humanitarian aid bound for Yemen’s north, where 80 percent of the country’s population lives. Defusing tensions there and restoring the port to full operation were widely seen as vital to assisting Yemenis and paving the way for a wider peace.

So when the warring sides shook hands Dec. 13, 2018, in Stockholm, it touched off a rare moment of collective hope.

But the terms of the deal were never fully implemented — and the war raged on.

“The Stockholm Agreement brought a glimmer of hope to civilians in the area, but the fighting is far from over,” Mariam Aldogani, Save the Children’s field manager for Hodeida, said in a statement last week. “Every day we receive wounded children in Save the Children-supported hospitals needing our care.”

This year, the charity said, it provided medical care to more than 500 children, some with life-threatening injuries. Children in Hodeida remain trapped by the fighting, and Save the Children had to close some of its centers for three months because of security fears, the group said.

“At one point this year we supported six children from two families — it was sad, some of the children had broken legs and shrapnel wounds all over their bodies,” Aldogani said. “I cannot forget the youngest girl, just 3 years old, with burns all over her hands. We need to stop this war on children.”

This year, the war grew more complicated as clashes broke out between armed groups within the Saudi-led coalition. UAE-backed southern separatists fought Yemeni government forces, who are backed by Saudi Arabia. The separatists seized control of the southern city of Aden, before Saudi Arabia persuaded the factions to sign a peace deal in Riyadh last month.

Now, the Riyadh agreement is seen as another opportunity to end the war. But Human Rights Watch said Thursday that the deal has failed to address serious human rights abuses, potentially deepening mistrust and undermining future peace efforts.

On Thursday, the aid agencies called for the Stockholm agreement to be speedily implemented. A nationwide cease-fire must be put in place, they said.

“If urgent action is not taken we could see another five years of conflict, leading to a greater catastrophe for civilians,” they said.