ANKARA, Turkey (AP) — Refugees fleeing the conflict in Syria once were welcomed in neighboring Turkey with open arms and compassion for fellow Muslims. But as their numbers swelled and Turkey became the host of one of the world’s largest refugee populations in the world, attitudes gradually hardened. Anti-immigrant sentiment now is spilling over into open aggression and violence. With prices of food and housing skyrocketing, many Turks are turning their frustration toward the country’s roughly 5 million foreign residents, particularly the 3.7 million who fled the civil war in Syria. In August, an angry mob vandalized Syrian-run shops and hurled rocks at refugees’ homes in response to a the deadly stabbing of a Turkish teenager.