Thank you Jura for your posts which have helped add context to the events; the sort of context usually left out of most Western media reports and which make understanding of the events much more difficult.
So the square where all this happened was a place of very special significance for those that opposed Fascism and the reason no doubt why a major Government building now occupies the site.
I picked up another very useful bit of context from RT
The key fact is the presence of Aleksey Albu; a local Regional Council Deputy and Mayoral Candidate and who was one of those caught up in the violence and trapped for a time in Trade Union House when it was set on fire.
This rather shows events in a very different light and totally blows open the inference given on the BBC that a Pro Maiden march of several thousand was attacked by Pro Russian march of several hundred, which was armed and fired indiscriminately into the Pro Maidan crowd.
Instead we have a small unarmed Political Rally at a Protest Camp, being addressed by a Pro Federalist Regional Politician and Mayoral Candidate, not an armed militant rally, being attacked by a much larger and largely bussed in, far right mob. I would further posit, that the four Pro Maidan fatalities in the afternoon due to gunfire, were the result of the armed bodyguards of significant local political figures having to fight off what looks now, rather more like an assassination attempt from riotous beginning to arsonist end.
Useful context? I think so, but I also know that hell will freeze over before you read that on the BBC!