The battle began with one or more car bombs set off inside the Syrian city. There are unconfirmed reports that Islamic State fighters hid themselves among refugees flooding into Kobani.
The U.S has sent humanitarian aid to help Syrian civilians, but only a small number of refugees have been allowed into America. Now the U.S. says it will increase the number of those admitted.
President Bashar Assad has suffered a series of recent military setbacks. But Hezbollah keeps fighting in alliance with Syria's army, and it scored a recent victory along the border with Lebanon.
The checkpoint at al-Tanf, known as al-Waleed in Iraq, has been seized, according to a British-based monitoring group that says ISIS fighters now control half of Syria.
Ancient ruins in the Syrian city captured by Islamist extremists could suffer the same fate as priceless artifacts that were destroyed in other cities seized by the group.
The raid, carried out on Saturday by U.S. forces, killed Abu Sayyaf, a senior commander. The Syrian Observatory for Human Rights says three other leaders were killed in ground and air operations.
The city is on UNESCO's World Heritage list and has been badly affected by the four-year civil war. The latest threat to Palmyra is posed by fighting between government troops and ISIS.
After four years of ebbs and flows in Syria's civil war, rebel fighters are pushing back the president's forces. He's having trouble replacing soldiers. And his allies may be providing less support.