German Chancellor Angela Merkel said on Friday on a visit to Lebanon that conditions in Syria are not yet right for refugees to return, an issue which has led to a dispute between Lebanon's foreign minister and the UN refugee agency.
A war monitor reported Syrian military helicopters dropped barrel bombs on rebel-held areas of the southwest on Friday for the first time in a year.
Syrian government forces and their Iran-backed allies will face "volcanoes of fire" if they launch a threatened offensive in the opposition-held southwest, a rebel commander told Reuters on Tuesday.
Syrian state media said on Monday that US-led coalition aircraft had bombed a Syrian army position near the Iraqi border, causing deaths and injuries, but the US military denied it was responsible.
The president was surrounded by dozens of worshippers who appeared to be offering him Eid greetings.
The Syrian army has reinforced its anti-aircraft defences near the frontier with the Israeli-occupied Golan Heights, a commander in the regional alliance that backs President Bashar al-Assad said on Tuesday.
Turkey has neutralized more than 4,600 militant during Operation Olive Branch in Syria's Afrin region, Turkish President Recep Tayyip Erdogan said.
More than 920,000 people were displaced inside Syria during the first four months of 2018, the highest level in the seven-year conflict, the UN said Monday.
The Islamic State group had lost ground Saturday in a town on the Syrian-Iraqi border after pro-regime forces repelled a major attack the day before, a Britain-based monitor said.