Could Islamic State's influence shatter Gaza ceasefire?

In the past week, several rockets have been fired at Israel from Gaza, endangering the 10-month-long ceasefire that ended last summer's deadly war.

Israel's Prime Minister, Benjamin Netanyahu, holds Hamas responsible for any rockets coming from Gaza - but Islamist extremists, who claim allegiance with Islamic State, have claimed responsibility for firing them.

Yolande Knell reports.