BAGHDAD — Tens of thousands of Syrian Kurds swarmed across a bridge into neighboring Iraq’s northern self-ruled Kurdish region over the past few days in one of the biggest waves of refugees since the rebellion against President Bashar Assad began, UN officials said Monday.
The sudden exodus of around 30,000 Syrians amid the summer heat has created desperate conditions and left aid agencies and the regional government struggling to accommodate them, illustrating the immense strain the 2½-year-old Syrian conflict has put on neighboring countries.
The mostly Kurdish men, women, and children who made the trek join some 1.9 million Syrians who already have found refuge abroad from the civil war’s relentless carnage.
‘‘This is an unprecedented influx of refugees, and the main concern is that so many of them are stuck out in the open at the border or in emergency reception areas with limited, if any, access to basic services,’’ said Alan Paul, emergency team leader for the Britain-based charity Save the Children.
‘‘The refugee response in Iraq is already thinly stretched, and close to half of the refugees are children who have experienced things no child should,’’ he said, adding that thousands of refugees were stranded at the border, waiting to be registered.
The United Nations said the reason for this flow, which began five days ago and continued unabated Monday, is unclear. But Kurdish areas in northeastern Syria have been engulfed by fighting in recent months between Kurdish militias and Islamic extremist rebel factions with links to Al Qaeda. Dozens have been killed.
Following the assassination of a prominent leader late last month, a powerful Kurdish militia said it was mobilizing to expel Islamic extremists.
On Monday, activists said fighters from Al Qaeda-linked jihadi groups shelled areas in the predominantly Kurdish town of Ras al-Ayn, coinciding with clashes in the area between Kurdish gunmen and jihadi fighters.
‘‘Syrian refugees are still pouring into Iraq’s northern Kurdish region in huge numbers, and most of them are women and children,’’ said Youssef Mahmoud, a spokesman for the UN refugee agency in Iraq’s Kurdish region. ‘‘Today, some 3,000 Syrian refugees crossed the borders, and that has brought the number to around 30,000 refugees since Thursday.’’
The latest wave has brought the overall number of Syrian refugees in the Kurdish region to around 195,000, he added.
The UN’s high commissioner for refugees has set up an emergency transit camp in Irbil, the capital of Iraq’s Kurdish autonomous region, to house some of the new arrivals.
The commission said it is sending 15 truckloads of supplies — 3,100 tents, two prefabricated warehouses, and thousands of containers to carry water — from its regional stockpile in Jordan. It said the shipment should arrive by the end of the week.