BRUSSELS, June 15 (Reuters) - The decision by some European Union countries to ban China's Huawei (HWT.UL) and ZTE (000063.SZ) from their 5G telecoms networks is justified and in line with the bloc's guidelines, EU industry chief Thierry Breton said on Thursday. Breton has in recent weeks voiced concerns that some EU countries still have perceived high risk components in their 5G core network, citing intrusive third-country laws on national intelligence and data security - a veiled reference to China. He has urged them to stick to EU guidelines adopted two years ago that call on member states to assess...