Thousands of Syrians fleeing the conflict in their homeland have streamed into northern Iraq in a sudden movement across a recently constructed bridge, the United Nations refugee agency reported today. Field officers with the UN High Commissioner for Refugees (UNHCR) reported the first group of some 750 Syrians crossed over the pontoon bridge at Peshkhabour at the Tigris River before noon on Thursday, but in the afternoon a much larger group of 5,000 to 7,000 people followed.“The factors allowing this sudden movement are not fully clear to us at this stage and as of this morning we are not seeing further large-scale crossings,” UNHCR spokesperson Adrian Edwards told reporters in Geneva.Some of the Syrians had reportedly been waiting near the Tigris River for two to three days, camped at a makeshift site. UNHCR monitors at the border saw scores of buses arriving on the Syrian side dropping off more people seeking to cross.Mr. Edwards said both the Syrian and Iraqi sides of the frontier at the Peshkhabour crossing are normally tightly controlled.The vast majority of the new arrivals are families, mainly from Aleppo, Efrin, Hassake and Qamishly. Some families told UNHCR they had relatives residing in northern Iraq, and some students travelling alone said that they had been studying in northern Iraq and had only returned to Syria over the recent Eid holidays.“UNHCR and partner agency teams, together with local authorities, worked into the early hours of this morning to aid the new arrivals,” Mr. Edwards said. UNHCR thanked Iraqi authorities and particularly the Kurdistan Regional Government for their involvement in negotiations to permit the new arrivals to cross and the transport and other assistance that was provided at the frontier.As of today, almost 2 million Syrians have fled the war and registered as refugees or applied for registration, with two-thirds of these having arrived this year. There are now more than 684,000 Syrian refugees in Lebanon, 516,000 in Jordan, 434,000 in Turkey, 154,000 in Iraq, and 107,000 in Egypt.UNHCR has urged countries in the region and elsewhere to keep borders open and to receive all Syrians who seek protection amid the fighting that has so far claimed over 100,000 lives since it began in March 2011.