(Reuters) -The United Nations welcomed on Thursday a ceasefire announced between Armenia and Azerbaijan after two days of violence linked to a decades-old dispute between the former Soviet states over the territory of Nagorno-Karabakh. The fighting, which each side blamed on the other, left more than 170 soldiers dead and threatened to drag Turkey, Azerbaijan’s key backer, and Armenia ally Russia into a wider conflict at a time of already high geopolitical tensions. A ceasefire was agreed between the two sides late on Wednesday after almost 48 hours of clashes, a senior Armenian official said….