Intensifying battles in Syria could create a “gigantic outflow" of refugees on a previously unseen scale, the U.N. refugee chief said Friday. “We all have seen crises of this nature in different parts of the world, let's hope that this doesn't evolve into the kind of gigantic outflows we have witnessed elsewhere," U.N. High Commissioner for Refugees (UNHCR) Antonio Guterres told reporters in Geneva. “Obviously, if the conflict intensifies, the capacity to deliver aid will be more and more limited," Guterres warned, adding that “contingency planning" was in place “for more dramatic situations." As many as 1.5 million people are internally displaced in Syria, but accessing them in conflict zones like Aleppo remains the most serious problem, the U.N. refugee agency said.