JERUSALEM — Prime Minister Benjamin Netanyahu told his Cabinet that Israel is still on alert against an attack from Sinai despite killing the man responsible for the plan, which unleashed more than 130 rocket attacks from Gaza on southern Israel.

The assassination by Israel’s military of Zuhir Mussah Ahmed Kaisi, the secretary general of the Popular Resistance Committee terrorist organization, led to rocket attacks from Gaza that continued into Sunday.

Netanyahu said Sunday that the targeted killing of Kaisi disrupted the organizing of the attack, but has led to a round of violence between Palestinian terrorist groups in Gaza and Israel.

“The IDF is striking at them in strength.  I would like to commend this operation and the security and intelligence services,” Netanyahu said Sunday.  “We have exacted from them a very high price; naturally, we will act as necessary.”

More than 130 rockets have been fired at Israel from Gaza since an Israeli airstrike on Friday killed Kaisi and another member of the Popular Resistance Committee. The men were responsible for planning a combined terror attack that was to take place via Sinai in the coming days, according to the IDF.

Eight Israeli civilians have been injured in the attacks, one severely, according to the Israel Defense Forces. At least 17 Palestinians, including a 14-year-old civilian, have been killed in Israeli attacks on Gaza.

Netanyahu praised the Iron Dome missile defense system, which according to the IDF has intercepted 90 percent of its targets, including 28 out of 31 long-range Grad rockets targeting major Israeli cities, including Beer Sheba, Ashdod and Ashkelon.

“I must also point out that the Iron Dome system has proven itself very well and we will, of course, see to its expansion in the months and years ahead. We will do everything in our power to expand the deployment of this system,” he said.

He also praised the residents of the southern Israeli communities for their resilience in the face of the rocket barrage.

“In the end, the strongest force at our disposal is the fortitude of the residents, of the council heads, of Israelis and of the government. We are taking the necessary defensive and aggressive measures and I have no doubt that with this combination, along with the necessary fortitude, we will overcome these terrorist threats around us.”

Netanyahu delivered a similar message Saturday night in a meeting with the mayors of southern Israeli communities.  He vowed to continue hitting Palestinian forces in Gaza responsible for the barrage of rocket attacks.

The IDF Home Front Command ordered schools closed Sunday in all cities and towns located up to 25 miles from the Gaza border, affecting about 200,000 children. Classes at colleges and universities in the area also were closed.

Since the violence began, the IDF as of Sunday afternoon, struck 21 targets in Gaza, including 13 airstrikes to halt rocket launching attempts and eight attacks against weapons factories and storage sites.

The United States is “deeply concerned by the renewed violence in southern Israel,” U.S. State Department spokesman Victoria Nuland said in a statement issued Saturday. “We condemn in the strongest terms the rocket fire from Gaza by terrorists into southern Israel in recent days, which has dramatically and dangerously escalated in the past day. We call on those responsible to take immediate action to stop these cowardly acts.”

“We regret the loss of life and injuries, and we call on both sides to make every effort to restore calm,” the statement concluded.

Egypt’s ambassador to the Palestinian Authority Yasser Othman told the Palestinian Ma’an news agency Sunday that Egypt was working to halt the escalation of violence between Gaza and Israel. He said his country was in contact with both sides in an attempt to stop the violence in order to “to avoid undesirable developments.” He also called Israel’s offensive “unjustifiable, and a breach to the truce sponsored by Egypt.”

The Popular Resistance Committees promised revenge for Kaisi’s assassination. “All options are open before the fighters to respond to this despicable crime. The assassination of our chief will not end our resistance,” Abu Attiya, a PRC, said.

“Israel’s escalation creates a negative atmosphere and increases the tension, which leads to the increase in violence in the region,” Palestinian Authority spokesman Nabil Abu Rudaina said, according to CNN.

The IDF issued a statement saying it holds “Hamas responsible for the recent incidents since the terror organization currently has jurisdiction in the area (Gaza).”

“We will continue responding to any attack against Israel,” the IDF spokesperson said in a statement. “The Hamas movement, although not the one performing the launchings, is not doing anything to prevent it either. We hold them responsible and will continue defending and attack as necessary.”

It is estimated that the long-range and mid-range rockets are being launched by Islamic Jihad terrorists, while the short-range rockets are being launched by the Popular Resistance Committee, according to the IDF.