Were the Israelis justified in the use of force in the First Intifada?

The uprising at the end of 1987 in Gaza and the West Bank, territories occupied by Israel after the Six-Day War, took both Palestinian and Israeli leadership by surprise.

Were the Israelis justified in using necessary and proportionate measures to restore order, or was their use of force, which included beatings and shootings, to repress a largely peaceful uprising unjustified?