CAIRO (AP) — Gunmen opened fire on a bus carrying Coptic Christians south of the Egyptian capital on Friday, killing 24 people and wounding 25, officials said. Following the pope's visit, the Islamic State affiliate in Egypt vowed to escalate attacks against Christians, urging Muslims to steer clear of Christian gatherings and western embassies as they are targets of their group's militants. Egypt's Copts, the Middle East's largest Christian community, have repeatedly complained of suffering discrimination, as well as outright attacks, at hands of the country's majority Muslim population.