Beirut ( CNN ) -- Syria carried out an airstrike on a refugee camp in northern Lebanon Saturday , killing nine Syrians and wounding nine more , a Lebanese state-run news agency reported . The strike centered on a Syrian refugee camp located near the Syrian border between the towns of Baalbeck and Arsal in the Bekaa Valley , the National News Agency said . The Red Cross took the casualties to Universal Hospital in Baalbek . Saturday 's strike was not the first by the Syrian government , which has accused rebels of smuggling arms and supplies across the border . On March 18 , two Syrian jets fired three rockets that hit empty buildings near Arsal . At the time , a U.S. State Department spokeswoman called the use of fighter jets to fire rockets into Lebanon a `` significant escalation . '' U.N. commissioner wants to probe into whether Syrian rebels executed soldiers . Also in March , the U.N. Security Council voiced `` grave concern over repeated incidents of cross-border fire which caused death and injury among the Lebanese population , incursions , abductions and arms trafficking across the Lebanese-Syrian border , as well as other border violations . '' The declaration followed a briefing by officials on how the conflict in Syria has spilled into Lebanon . More than 600,000 Syrians have fled to neighboring Lebanon , a country of about 4 million people , according to a U.N. estimate . But the Lebanese government puts the total at more than 1 million . Whatever the true figure , there is no dispute that the influx has destabilized the area and heightened tensions . The attack comes as the Syrian conflict is mired in a third year of unrest , which started in March 2011 when President Bashar al-Assad cracked down on peaceful protesters . Since then , it has evolved into a civil war that has killed more than 100,000 and transformed more than 1 million others into refugees , according to the Red Cross . Read more : U.N. inspectors heading to Syria to probe chemical weapons reports . CNN 's Nick Paton Walsh reported this story from Beirut , and Tom Watkins wrote it in Atlanta . CNN 's Hamdi Alkhshali and Yousuf Basil contributed to this report .
Airstrike kills nine Syrians in refugee camp , state media reports . Syria has fired into Lebanon before . Comment: