KYIV, June 10 (Reuters) - Counterattacking Ukrainian forces have advanced up to 1,400 metres at a number of sections of the front line near the eastern city of Bakhmut in the past day, a military spokesman said on Saturday. The advance is the latest in a series of similar gains reported this week by Kyiv near Bakhmut, which Russia said it had fully captured last month after the bloodiest and longest battle since it began its full-scale invasion in February 2022. Britain's Ministry of Defence said that Ukrainian forces have penetrated the first line of Russian defences in some areas but that Kyiv's progress had been slower in others