PITTSBURGH (AP) - A gunman who's believed to have spewed anti-Semitic slurs and rhetoric on social media barged into a Pittsburgh synagogue on Saturday and opened fire, killing 11 people in one of the deadliest attacks on Jews in U.S. history.

The 20-minute attack at Tree of Life Congregation in the Squirrel Hill neighborhood left six others wounded, including four police officers who dashed to...