A report Thursday accused Bulgarian authorities of brutal treatment toward migrants traveling across the Balkans. Citing testimony of migrants crossing through Bulgaria into Serbia, the report alleges several incidents of police beatings, physical violence against migrants, attacks by police dogs, and extortion. The Bulgarian government has yet to respond to the allegations. The report, sponsored by the British charity Oxfam, is based on interviews conducted with more than 100 refugees arriving from Bulgaria in the Serbian border town of Dimitrovgrad. Last month, an Afghan migrant was fatally shot by a Bulgarian border official after crossing over from Turkey.