The Assad regime and an umbrella organisation representing a large number of rebel groups have agreed to the terms of a truce deal, which would pause hostilities from Saturday.
Russia “categorically rejects” allegations of war crimes over the bombing of four hospitals and two schools in Syria on Monday.
As many as 50 people, including 12 children, have been killed in missile attacks on three separate hospitals in northern Syria.
A hospital in the north-western Idlib province of Syria supported by Medecins Sans Frontieres (MSF) has been destroyed in a Russian air strike.
The 2006 murder of former Russian spy Alexander Litvinenko was “probably” organised by Moscow’s FSB intelligence service and approved by Russian President Vladimir Putin, a public inquiry has concluded.