The U.N. peace envoy for Syria will host senior officials from a range of Western and Middle-Eastern countries next month for talks on drafting a new Syrian constitution, the U.N. said Tuesday.

Moscow is reinforcing its military presence in the Mediterranean near Syria, Russian media reported Tuesday, as speculation grows that Damascus is planning a Russian-backed offensive on rebel-held Idlib province.

A truce has been reached after deadly clashes erupted between rival militias in Tripoli, a security source said Tuesday as residents reported calm had returned to Libyan capital.

Four years after announcing its cross-border "caliphate" in Iraq and Syria, a stinging string of defeats has pushed the Islamic State jihadist group to reorganize and change strategy to survive.

Israeli forces demolished the home of a Palestinian who carried out a deadly knife attack in a settlement in the occupied West Bank, the army said Tuesday.

Heavy air strikes targeted the international airport in Yemen's rebel-held capital and an adjacent airbase early Tuesday, residents said, with rebels blaming the Saudi-led coalition fighting on the side of the government.

All sides in Yemen's bloody conflict may have committed war crimes, UN investigators said Tuesday, highlighting deadly air strikes, rampant sexual violence, and the recruitment of young children as soldiers.

In their first report, a team of UN-mandated investigators said they had "reasonable grounds to believe that the parties to the armed conflict in Yemen have committed a substantial number of violations of international humanitarian law."

Russia's defence minister said on Tuesday that war-torn Syria would be ready to accept one million returning refugees, following Moscow-backed reconstruction work. 

"Since 2015, when towns and villages gradually started to be freed, more than one million people have returned home," Sergei Shoigu said in comments reported by Russian news agencies.

Russia and Turkey are in intense negotiations to ensure the rebel-held province of Idlib does not become a breaking point in their alliance on Syria, but the long term fate of the area still risks provoking a rupture, analysts say.

Iraq's parliament will meet next week for its first session since May elections to choose a speaker and begin the process of forming a government, the outgoing president said Monday.