This is a sad, but little told story. In 1943, at the request of the Emperor Haile Selassie, the Royal Airforce bombed two towns – Mekelle and Corbetta.
The source for this information is an article by Aregawi Berhe, in African Affairs – the journal of the Royal African Society, from 2004.
Further details can be found in an earlier article by David Killingray.
The RAF squadron that carried out the raid may actually have been carried out by Canadians from number 8 Squadron.
This information is from a publication called Legation: Canada’s Military History Magazine.
“In this strange colonial world the Canadians experienced things never imagined when they enlisted…On Sept. 1, 1943, a request was received from the Emperor of Ethiopia for aircraft to drop leaflets in Macaille and eastern Tigre province prior to operations against rebellious tribes. No. 8 Sqdn., another Bisley unit and normally based in Aden, operated a three-plane detachment from Addis Ababa and spent several days bombing rebel concentrations and native hutments. One of the wireless air gunners was Flight Sergeant Joseph Leon Belley of Quebec City. This squadron was the destination for numerous Canadians. Indeed, as of December 1943 at least 19 members of the RCAF had been posted there.”
When in 1942–43 peasants in central and southern Tigray began to rebel out of desperation, they were met with a harsh response. Haile Selassie’s government in collaboration with the British Royal Air Force (RAF), after dropping warning leaflets addressed to ‘the Chiefs, Balabats — people of Tigre province’ on 6 October 1943, devastated the region including Mekelle, the capital of Tigray, throughout the rest of that month.
This quelled the Tigrayan peasant uprising, known as Woyane, meaning ‘revolt’.
Thousands of defenceless civilians lost their lives as a result of aerial bombardment. It is recorded that ‘on 14th October  54 bombs dropped in Mekelle, 6th October 14 bombs followed by another 16 bombs on 9thOctober in Hintalo, 7th/9th October 32 bombs in Corbetta’.
Repression did not stop there.
The people of Tigray region were forced to pay large sums of money and their land was confiscated and distributed to loyal gentry as a punishment and as a deterrent to future revolt. A new taxation system was imposed that ‘cost the peasants five times more than they had paid under the Italians’.
In the name of centralization, Haile Selassie took away regional power from hereditary leaders and gave it to loyal Showan administrators.
This predicament again raised the level of collective resentment, taking the form of ethno-nationalist sentiment against the Showan ruling class at the centre. As Gilkes rightly observed, ‘independence from Shoan (sic) rule was raised as a rallying cry and proved popular’.
The punitive measures of the central government, and especially the memory of the RAF bombardment of Mekelle on behalf of Haile Selassie’s government, became grievances rooted in popular memory.