JERUSALEM — The Israeli authorities announced Monday that five Palestinian members of the militant group Hamas had confessed to fatally shooting an Israeli couple in front of their four children last week, as the intensifying violence that that attack touched off stretched into a fifth day, with Israeli forces fatally shooting two Palestinian teenagers — one 13.

“We will act with a very harsh hand against terror and also against incitement,” Prime Minister Benjamin Netanyahu of Israel said in a televised statement praising the arrest of the Hamas members. “We will not give any rioter or any inciter immunity in any place, and so there are no limitations of the actions of the defense forces.”

Both Mr. Netanyahu and President Mahmoud Abbas of the Palestinian Authority convened emergency meetings Monday night to discuss the deteriorating security situation. Neither the Israeli crackdown nor the Palestinian uprising showed signs of abating: The Palestinian Red Crescent Society reported some 500 injuries in recent days as clashes raged. Pathways through the West Bank and East Jerusalem were cut off by new Israeli roadblocks, as well as by burning tires and stones hurled by Palestinian youths.

Wafa, the official Palestinian news agency, reported that Mr. Abbas told members of his military council and leaders of his security apparatuses to be wary of Israeli efforts to inflame the situation and drag the region into a new cycle of violence. Earlier, Ahmed Majdalani, a member of the Palestine Liberation Organization’s executive committee, said on Voice of Palestine radio, “Israel is continuing with its escalation based on the rule saying what cannot be taken by force will be achieved with more force.”