The international community is demanding UN access to the site of an alleged chemical attack in Syria.
The Syrian army, backed by Lebanese Hezbollah fighters, has entered the rebel-held town of Zabadani on the border to Lebanon. Capturing the town would be a boost to the government after several setbacks.
Syrian rebel groups have launched a joint attack of government-held sites in Aleppo. Monitors say it is the largest such assault in two years. The northern city has been divided between the regime and rebels since 2012.
Syrian army forces are fighting to maintain control over Aleppo, the country's former financial capital. Rebels are also battling President Assad's forces to recapture Zabadani, on the Syrian border with Lebanon.
The US is targeting the "heart" of the IS, US President Barack Obama said after a briefing with top military and security officials. After losing ground, the jihadists struck back against Kurdish forces in Syria.