MAZRAQ, YEMEN — It was sometime after 2 a.m. when gunfire and mortars startled Oqaba Mohammed out of sleep. She thanked God she was alive and quickly gathered her four children, walking into the night and away from the only home she had ever known.
"We had nothing but the clothes on our bodies, but I didn't look back," said Mohammed, who had carried her physically disabled daughter in one arm and her 15-month-old son in the other. "We walked for three days, from village to village, asking for food from ordinary people. And then we arrived here."
Mohammed and her family were among the first wave of displaced Yemenis to make it to Mazraq, a United Nations camp in the northwestern province of Hajjah, where 7,000 people now live. They have fled the war in nearby Saada province, where the nation's army, after five years of sporadic warfare in the region, has launched what it calls a final offensive against a Shiite Muslim rebel group called Houthis.
The latest round of violence near the border with Saudi Arabia, which began in mid-August, has brought some of the most intense fighting since the war began.
A poor but strategic country on the Gulf of Aden, Yemen is increasingly unstable. Washington is concerned about the government of President Ali Abdullah Saleh being embroiled in conflicts that include a separatist insurgency in the south and growing numbers of Al Qaeda fighters using the nation as a base to launch attacks across the Middle East.
The Houthi revolt plays into broader politics and animosities. Yemen has made veiled suggestions that Shiite Muslim Iran is supporting the rebels, who belong to a Shiite sect. And Sunni Muslim-dominated Saudi Arabia worries that the unrest could creep across its border, further adding to its suspicions that Iran is instigating trouble across the region.
An estimated 30,000 people have fled the northwest in the last two months, many for the second or third time, bringing the number of people displaced by this war to more than 150,000, according to news reports and United Nations records.
About 65,000 displaced people are in Hajjah and an estimated 55,000 are still living in the war zone in Saada, said Yemen-based U.N. refugee officer Andrew Knight. Many of those in Saada are living in abandoned buildings, in the mountains and on roadsides.
Mazraq is the only United Nations camp for the displaced in Yemen. For security reasons, the government -- and local and tribal leaders concerned about their autonomy and the use of their lands -- has largely barred U.N. convoys from Saada and Amran provinces.
Since it opened at the start of the fighting in August, Mazraq has grown to twice the number of residents that camp authorities expected, and it accepts 200 additional people a day.
About 40% of camp residents suffer from diarrhea, 20% of the children are malnourished, and the spread of malaria is a growing concern. There is no running water or electricity, and most families have had to dig holes near their tents for use as outhouses.
"Because of the surge of people, we are unable to keep up," said Jobran Yahya Doraini, deputy manager of the camp.
"We have 80% of the supplies we need, but with all the newcomers, there are more and more shortages every week."
As of Friday, 210 families didn't have a tent and the vast majority did not have access to water filters, said Hamood Mohammed Musawa, a camp administrator.
Most families share tents with neighbors and extended families. They drink the water that comes in giant tanks and is the color of iced tea.
Almost half of the adults and children in Mazraq suffer from chronic diarrhea as a result of unsanitary conditions, unfiltered drinking water and poor nutrition, said Victor Abdul Salam Jamah, chief of the medical team in Mazraq, which is funded in part by the World Health Organization and the government. Last week, his staff diagnosed the first case of malaria.
Jamila Hamid Hassan, her husband and their nine children fled their home in Al Dhahir three weeks ago. Their son Ala, 15, was caught in crossfire when he and Hassan's husband returned to check on their house. He was hit by shrapnel in the stomach and shoulder but survived.
"At least the children are all together," Hassan said. "Maybe that is enough."
U.N. Undersecretary-General for Humanitarian Affairs John Holmes, who visited Mazraq last week, said the main concern is reaching people trapped in the war zone.
"What we need is full access to all the areas, to all displaced people," he said, looking to local and tribal authorities to help break the blockade. "It's a very complex issue. It's not a matter of a simple refusal by the central government."
On Sunday, the first U.N. aid convoy was allowed to enter Saada through the Saudi border, Holmes said. The Yemeni government says it has opened safe corridors to provide aid, but security concerns have delayed the opening of a second displacement camp in the village of Khaiwan in Amran.