REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE CONTENT OF THIS VIDEO WHICH HAS BEEN OBTAINED FROM A SOCIAL MEDIA WEBSITE<br/> <br />Amateur video, which cannot be independently verified by Reuters, appears to show a rebel launching a rocket-propelled grenade near the border with Turkey.<br/> <br />The rebels have been fighting since Friday for control of the Kasab crossing.<br/> <br />State media reports a cousin of Syrian President Bashar al-Assad was killed in Latakia, near the border with Turkey, in battles with Islamist rebels.<br/> <br />State television described him as the head of the National Defense Force in the coastal province of Latakia, where the Assad family come from.<br/> <br />Another amateur video purportedly shows rebels firing at a government aircraft in the al-Turkman mountains.<br/> <br />Their tank is camouflaged in the trees.<br/> <br />On Sunday, Turkish armed forces shot down a Syrian plane, saying it had crossed into its air space. Syria said the jet was pursuing rebel fighters in the area.