BRUSSELS, Oct 14 (Reuters) - The European Union"s executive summoned envoys from member states Poland, Lithuania and Latvia on Thursday over the fate of migrants stuck on their border with Belarus. "I"m very concerned about reports of people including children stuck in forests in dire situation at external EU borders with Belarus," European Home Affairs Commissioner Ylva Johansson said in demanding a meeting with the three national ambassadors to EU hub Brussels. The three countries have reported sharp increases in the number of migrants from Africa and the Middle East crossing into the soil from Belarus in recent months. The EU blames Belarus for deliberately orchestrating the flow to put pressure on the bloc in retaliation for sanctions it had slapped on Minsk over human rights abuses.