The plane bringing home Corporal William Savage, Fusilier Samuel Flint and Private Robert Hetherington has just landed at RAF Brize Norton.
Close family will spend time with the coffins before the cortege passes through the village of Carterton where friends and family will pay their respects as a memorial bell tolls.
More top news
Cloud and outbreaks of rain will ease away eastwards during the morning, clearing the east coast around midday with sunny spells developing.
Police and emergency services are attending the scene.
Rebel-held east remains at risk while the pumping station supplying the western part of the city is once again in operation.