Yemen is in despair.

The latest escalation in conflict has left neighbourhoods around the country completely destroyed. Hospitals, schools, mosques and humanitarian infrastructure lie in ruins. More than 1,000 innocent lives have been lost and tens of thousands more have brushed death, as they face the impact of nearly one month of devastating air strikes. This is why the last thing Yemen needs is more violence and instability, and why we're calling for an immediate end to the violence.

Indeed, the horrifying events that have brought us here linger in an unfolding humanitarian catastrophe, one that threatens to claim the highest death toll of all.

I can honestly say I have never faced anything like this. I'm from Glasgow, but I have lived in a few places having served as Oxfam's country director in Afghanistan, Indonesia, Lebanon, Malawi, Myanmar, Sierra Leone and now Yemen. I have seen countries devastated by war and have worked hard with others to address the suffering that follows. But this time is different. This time everyone was caught off guard. Infrastructure has crumbled and our ability to respond at full scale has been blocked. At Oxfam we are concerned now, more than ever before, about the ability of Yemen's poor to survive the challenge they face.

While other crises in the Middle East command a higher profile, the fact remains that one person in three in need of humanitarian assistance in the region was already in Yemen, even before the latest round of conflict. More than 60 per cent of the population - that's 16 million people - were in need of aid. More than half the population did not have access to clean water and sanitation. One in three did not have access to adequate health care.

Oxfam's priority is gaining access to deliver life-saving humanitarian assistance to as many people as possible. But the fighting is not over. While I welcome this week's announcement from the Saudi-led coalition de-escalating the conflict, there is still no ceasefire. Air and sea routes, vital access points for the delivery of humanitarian supplies and essential imports remain closed. Oxfam is ready to move but we need access and we need it now. We're using all the resources in our global network to press those with the power to lift this blockade and provide safe humanitarian access immediately.

More than 12 million Yemenis, more than double the population of Scotland, do not have enough food to eat. Here in Yemen there is no such thing as a welfare system unless you count the roughly £13 per month the poorest of families receive from the Social Welfare Fund, and even that has ground to a halt.

The country's infrastructure is in shambles as existing humanitarian needs are rocketing. Hospitals are stretched to the limit, lacking essential medicine, personnel and equipment. Community water supply systems have been heavily damaged, leaving entire communities without water. Millions more have been forced into hunger as food prices now spiral out of control, created by the absence of imports upon which Yemen relies to meet 90 per cent of national food consumption. Fuel has virtually disappeared from the marketplace, making water and food more difficult to access. Electricity is only for on a few hours a day at best. Yemen is paralysed.

This all makes it very difficult for us to reach those in need of life-saving assistance. But with the efforts of our Yemeni staff, who have remained dedicated in the face of injury and loss of loved ones, Oxfam has reached more than 60,000 people with essential cash and the provision of clean drinking water despite the heavy conflict over the past month. But with millions in need, this is a drop in the ocean.

When I first arrived in Yemen in October 2014, I was greeted by sunshine and warm smiles. I was so impressed with the genuine hospitality of the Yemenis who came into my life; all beautiful people whom I am now extremely concerned for as they face the mounting devastation of continued conflict.

Grace Ommer is Oxfam's Country Director in Yemen.

http://donate.oxfam.org.uk/emergency/yemen