(CNN)The city of Deir Ezzor in northern Syria has seen more than its share of conflict and suffering since the Syrian insurgency began. But the last few days have seen unprecedented horror, according to human rights activists, with suicide bombings, mass abductions and arbitrary killings.
Most of the city has been controlled by ISIS for well over a year, but some neighborhoods and the military airport to the south have remained in the hands of the regime. In recent weeks, ISIS has stepped up offensives against several of these areas. And in the last few days it has overrun several neighborhoods, capturing and killing dozens of Syrian soldiers but also seizing many civilians, according to reports from activists.