Explainer: How Jerusalem tensions sparked heaviest Israel-Gaza fighting in years

Weeks of violent clashes in East Jerusalem have ignited the heaviest fighting in years between Israel and Palestinian militants in the Gaza Strip.

At the core of the violence that has left dozens dead are tensions between Israelis and Palestinians over Jerusalem, which contains sites sacred to Judaism, Islam and Christianity.

As both sides appear to be digging in for more prolonged fighting, here are some of the factors that triggered the escalation...