Abdullah al-Osaimi worries every day about how to put food on the table for his wife and four children.
The family fled several months ago from their home in Yemen's Noqm neighbourhood, east of the capital Sanaa, amid ongoing air strikes by the Saudi-led Arab coalition battling the country's Houthi rebels. They eventually resettled in a school housing internally displaced persons in the heart of Sanaa.
Houthi fighters accused of blocking aid in Yemen
"The problem of being homeless has been solved, but we are unable to find a solution for the most critical problem we face: accessing food and clean water," Osaimi, a 45-year-old unemployed salesperson, told Al Jazeera. When his family fled Noqm, they left behind their home, his small shop, and almost everything inside.
Osaimi has since eked out a living by selling bottles of water to pedestrians in Sanaa, quickly burning through his small savings of around 10,000 Yemeni rials ($50).
"I have become unable to provide food to my family - even the basic needs, such as plain bread and water," Osaimi said.
Since March, an Arab coalition led by Saudi Arabia has been conducting air strikes in Yemen in an effort to curb the expansion of the country's Houthi rebels, who have been fighting government forces for control of the country. Thousands of people have died in the conflict, which has sparked a massive humanitarian crisis. More than 1.5 million people have been displaced, and many more are struggling to access the basic necessities, including food, water and fuel. 
According to the World Food Programme (WFP), around 14 million people in Yemen - more than half the country's population - have become food insecure, and of those, around seven million are classified as severely food insecure.
"It's a country that cannot take any further shock," Abeer Etefa, the WFP's spokesperson for the Middle East region, told Al Jazeera. "It's a very serious situation. We are doing our best so that we don't see a deterioration of the situation that's already extremely compromised."
This map shows acute food security outcomes as per the Integrated Food Security Phase Classification in Yemen in October 2015 [FEWS NET]
Ongoing fighting has made it difficult for relief agencies to reach the areas of greatest need, while several key land border facilities have been closed, and Houthi rebels have laid siege to the southwestern city of Taiz. Access routes throughout the country, including many bridges, have been damaged or destroyed, contributing to the worsening food shortages, noted a report released this month by the Famine Early Warning Systems Network (FEWS NET). 
The report found that the problem of food insecurity in Yemen, a country that has long struggled with malnutrition and poverty, has deteriorated substantially since last year - and the decline is set to continue.
By mid-October, average wheat flour prices were 47 percent higher than the February average, the report noted, while diesel prices in October were 270 percent higher than in February. At the same time, household income has fallen as residents struggle to make a living.
"A continuation of current trends of reduced household income and increased food prices could lead to deteriorating food security outcomes in the coming months," the report stated, noting many residents in southern and western Yemen are facing an "emergency" state, the second most severe category of food insecurity after "catastrophe/famine". The situation is particularly grave for displaced people and those trapped in active conflict zones.
The problem of being homeless has been solved, but we are unable to find a solution for the most critical problem we face: accessing food and clean water.
Abdullah al-Osaimi, displaced resident
"The risk of acute malnutrition also remains high due to the high disease burden and reduced access to healthcare... The scale of current needs is well beyond response capacity."
Peter Salisbury, a journalist and analyst with Chatham House who specialises in the Yemen conflict, said the situation has become dire for many Yemenis.
"A big chunk of the population is now on the verge of starvation," Salisbury told Al Jazeera. "The international community has been trying to bring aid in, but the bigger issue has been getting commercial volumes of food and fuel into the country."
Amid an arms embargo, some large commercial ships have been blocked from entering Yemen, Salisbury said, even as the United Nations and others have attempted to speed up the inspection process.
"If the war continues, as looks likely, and the inward flow of trade doesn't improve, it can only get badly worse," he said. "We are talking about famine among the poorest and least accessible people in the country, and a huge population of internally displaced people. That also means huge long-term consequences for the health and economic prospects of Yemenis... Malnutrition slows down kids' mental and physical development and Yemen has a very young population."
According to FEWS NET, parts of Yemen have been witnessing exceptionally high levels of morbidity among young children, along with a rise in cases of malnutritioned children. Data from Abyan governorate revealed a fourfold increase in admissions of malnourished children this year, from 136 in 2014, to 557 in 2015; similar trends were seen in other Yemeni hospitals. 
Etefa says the WFP has been working with the Arab coalition and other partners on the ground to ensure food shipments are distributed across the country, but funding and access remain major problems.
"The situation changes on a daily basis," she said. "Some days we have better access than others and when a window of opportunity opens, we race against time to get food to people who desperately need [it]... We fear that if we cannot continue to address the needs immediately, we definitely will see increasing levels of hunger and food insecurity in Yemen."
Back in Sanaa, Om Hussein, 55, who lives in the city's Shumaila district, appeared exhausted as she carried a large plastic container of water towards her home. Due to shortages of oil used to power water pumps, she can no longer access clean water at home.
"Every day, I wake up heading for the well located [nearly 5km] from my house, to bring water for drinking and cooking," Om Hussein told Al Jazeera. "We are no longer able to remember what the water looked like coming out of the faucets in my house."
of Sanaa, in the conflict-ravaged Taiz governorate, 25-year-old Yaseen Yahia says his family has gone down to eating just one meal a day. 
"Most of the families in Taiz, because of the Houthis' siege and the war, have faced the same destiny," Yahia told Al Jazeera. "How could we manage to have access to food and clean water? In such a situation, we are hoping just to survive, rather than searching for a loaf of bread."
As for water, Yaseen says it is periodically trucked in from other governorates, allowing locals to fill their containers.
"The truck drivers always narrowly make their way amid the Houthi checkpoints erected in the entrances of the city," Yahia said. "A surge of people of all ages and genders eagerly flock to the trucks, bearing water containers of different sizes and shapes to bring water back to their homes. It is an unforgettable moment."