Syrian regime air strikes killed five civilians including two children Sunday in a northwestern bastion of the opposition, a war monitor said.

Rocket fire has killed 12 civilians in a regime-held village in northwestern Syria, state news agency SANA has said blaming former Al-Qaeda affiliate Hayat Tahrir al-Sham for the attack.

A Turkish observation post in Syria's Idlib region was attacked with mortar fire and shelling from an area controlled by Syrian government forces, causing damage but no casualties, the Turkish Defence Ministry said on Sunday.

Mediterranean countries say they have taken a key step towards finding out the fate of thousands of migrants -- many fleeing Syria's war -- who have gone missing while trying to reach Europe.

Syrian officials have refused access to a newly-created chemical weapons investigation team formed to identify culprits behind attacks with banned munitions, the organisation's top official said in remarks published on Wednesday.

Twelve orphaned children of French jihadists were flown home Monday from Syria, along with two Dutch orphans who will be handed over to the Netherlands, the French foreign ministry said.

A Iraqi court Monday sentenced to death two more French nationals for joining the Islamic State group, leaving all 11 Frenchmen transferred from Syria facing the gallows and potentially opening the door for other cases.

The US-led coalition said Friday it had unintentionally killed more than 1,300 civilians in air strikes during its fight against the Islamic State group in Iraq and Syria since 2014.

The latest strikes in the fiercest wave of regime bombardment on a militant enclave in northwestern Syria killed at least 15 civilians on Wednesday, a war monitor said, despite calls to halt the attacks.

Air strikes stopped in northwest Syria over the past 12 hours, rescuers said on Saturday, as Turkey-backed rebels arrived at the fronts to help fight the army and its Russian ally.

Clashes on the edge of a militant bastion in northwestern Syria have killed 35 fighters in 24 hours, a monitor said Monday, after regime bombardment on the region devastated health services.

Bangladesh's counter-terrorism police have arrested a suspected Islamic State member who returned to the country after fighting for the militant group in Syria, police said Wednesday.