JERUSALEM — A Palestinian youth sneaked into a fortified Jewish settlement in the West Bank on Thursday, broke into a home and stabbed to death a 13-year-old Israeli-American girl as she slept in bed before frantic security guards arrived and killed him.

The girl, identified as Hallel Yaffa Ariel, became the youngest Israeli victim of a nine-month wave of violence that has seen dozens of Palestinian attacks.

The early-morning stabbing, carried out by a 17-year-old Palestinian high school dropout, was among the most brazen attacks so far, drawing angry accusations and calls from Israeli leaders for the world to condemn the incident.

Israel has a large community of dual American citizens, numbering in the tens of thousands.