On 19 March 1921, Tom Barry's 100-strong West Cork IRA unit fought an action against 1,200 British troops – the Crossbarry Ambush. Barry's men narrowly avoided being trapped by converging British columns and inflicted between ten and thirty killed on the British side. Just two days later, on 21 March, the Kerry IRA attacked a train at the Headford junction near Killarney. Twenty British soldiers were killed or injured, as well as two IRA men and three civilians. Most of the actions in the war were on a smaller scale than this, but the IRA did have other significant victories in ambushes, for example at Millstreet in Cork and at Scramogue in Roscommon, also in March 1921 and at Tourmakeady and Carowkennedy in Mayo in May and June. Equally common, however, were failed ambushes, the worst of which, for example at Mourneabbey, Upton and Clonmult in Cork in February 1921, saw six, three, and twelve IRA men killed respectively and more captured. The IRA in Mayo suffered a comparable reverse at Kilmeena, while the Leitrim flying column was almost wiped out at Selton Hill. Fears of informers after such failed ambushes often led to a spate of IRA shootings of informers, real and imagined.