VILNIUS, Lithuania—Lithuania has ordered its border guards to turn away, by force if needed, migrants attempting to enter the Baltic country as the rapidly growing number of immigrants illegally crossing from neighboring Belarus has emerged as a major foreign policy issue to the small European Union nation. The Interior Ministry distributed a video footage shot from a helicopter as proof that large groups of immigrants were being escorted to the European Union border by vehicles belonging to Belarus’ border guard authority. Lithuania says the migrant influx in the past months is an act of retaliation by Belarus’ authoritarian President Alexander Lukashenko to increased sanctions by the EU toward his country over an air piracy incident. Lithuania’s Interior Ministry said Tuesday that at least three large migrant groups were stopped in thick woods in the border area between the two countries, and Lithuanian border guards commanded them to return back to …