Oct 3 (Reuters) - Ukrainian forces have made some breakthroughs in the southern Kherson region and taken control of some settlements, a Russian-installed official said on Monday."Where the Kakhovka (reservoir) is, there is a settlement called Dudchany ... it is in this area that there is a breakthrough and there are settlements taken by Ukrainian troops," he said.Register now for FREE unlimited access to Reuters.comDudchany, on the west bank of the Dnipro river, is about 40 km (25 miles) downriver from where Russian troops had opposed Ukrainian forces a day earlier.read moreUkrainian officials have been tight-lipped about the scale of their counter-offensive in the south, but Russian military bloggers have described Ukrainian tanks advancing along the bank of the Dnipro river.Russia formally moved to annex four Ukrainian territories last week, including Kherson region, but none are fully under the control of Moscow's forces and Ukraine continues to wage a counter-offensive in the south and east."