On the third day of fighting after Hamas militants launched surprise rocket and ground assaults, Israel ordered a complete siege of the Gaza Strip, even as its military was still trying to remove Hamas gunmen from small Israeli communities along the enclave’s border.

Israeli Defense Minister Yoav Gallant told the Southern Command there would be a “full siege” over the densely populated enclave, which has a population of 2 million, bordered by Israeli fences and the sea.

“No electricity, no food, no fuel. We are fighting animals, and we will act accordingly,” Gallant said Monday, underscoring the all-out measures that many Israelis are demanding.

Israeli Energy Minister Israel Katz issued an order “to immediately cut off the water supply from Israel to Gaza.” Electricity and fuel supplies were cut off Sunday, Katz added.

Gaza gets most of its electricity from Israel, though the strip does have one aged power plant. The enclave has groundwater sources, but many wells have become ruined by pollution and saltwater. More than 90 percent of the water in Gaza’s sole aquifer is no longer potable.

There was no sign that Hamas was de-escalating. Air raid sirens blared in Jerusalem and Tel Aviv as Hamas launched salvos at the two cities, appearing to flex its ability to continue striking at the heart of Israel.

Explosions were heard in Jerusalem, alongside sonic booms, indicating the activation of Israel’s Iron Dome air defense system. Rockets also landed in southern towns, including Ashkelon.

Projectiles landed in Tel Aviv and in Jerusalem in open areas, as well as on Highway 1, the main route connecting the two cities. Emergency services have not yet recorded reports of casualties. The country’s main airport remained open, but many carriers canceled flights.

As Israeli troops and tanks head toward the Gaza border, Hamas fighters continued to infiltrate the border and might be entering Israeli territory, Lt. Col. Richard Hecht, a spokesman for the Israel Defense Forces, said at a news briefing Monday.

“We are still fighting. We thought this morning that we would be in a better place,” Hecht said. “We still have open areas. I can’t say that they’re not still coming in.”

Hecht said it was taking Israeli forces “more time than we thought” to repel Hamas fighters, in part because of the presence of civilians. “This is not military fighting militants. There are civilians in the midst of it. … We are doing it in a very surgical way. It is taking a lot of time.”

The Israeli military said “most” of the breach points have been secured.

Masha Michelson, deputy head of the IDF for the international media, said Israeli forces “have reestablished control of communities near the Gaza Strip … but isolated clashes continue as some Palestinian gunmen remain active.”

On Sunday, the Israeli media said more than 100 Israelis had been “kidnapped,” with most taken into Gaza. In briefings on Monday, the IDF spokesman confirmed “several dozens.”

“This is something different — unprecedented,” Hecht said. “And it’s not soldiers [being held hostage]. … It’s a grandmother, a child, a family, a girl.”

Searching for ways to describe both the scale and surprise of the Hamas attacks, Israeli officers and diplomats repeatedly compared Saturday’s raid to the Japanese attack on Pearl Harbor and to 9/11.

Lt. Col. Jonathan Conricus, an IDF spokesman, told the BBC that “this could be a 9/11 and a Pearl Harbor wrapped into one.” He called it “by far, the worst day in Israeli history. Never before have so many Israelis been killed by one single thing let alone enemy activity on one day.”

Israeli authorities say that some 700 people have been killed in Israel since Hamas launched its attacks on Saturday morning, including 73 soldiers and 260 people attending a music festival near the Gaza border.

The U.S. State Department announced that nine U.S. citizens have been killed in the fighting between Hamas and Israel. Spokesman Matthew Miller also said that “there are unaccounted-for U.S. citizens, and we are working with our Israeli partners to determine their whereabouts.”

Palestinian health officials reported Monday that 560 people have been killed in Gaza since the Israeli airstrikes began. The number of wounded Palestinians has risen to 2,900.

The Israeli air force said Monday that it struck more than 500 Hamas and Islamic Jihad targets in Gaza overnight, including seven Hamas command centers and one used by Islamic Jihad.

Inside Gaza, residents spent another terrifying night, feeling and hearing the Israeli bombardment from aircraft, artillery and naval ships.

Homes belonging to known Hamas leaders have been leveled. At least two mosques were destroyed. Thousands crowded into schools, seeking shelter. The main hospital in Gaza City was also filled with panicked refugees, alongside the sick and wounded.

The crossing from Gaza into Egypt remained partially open Monday and was overwhelmed with people trying to flee. Internet lines were severed, electricity was sporadic, water tanks running dry. The United Nations said Monday that more than 123,000 Gazans had been displaced from their homes.

Most of Gaza’s fresh fruit and vegetables come from the farms along its border with Israel. With an invasion, those fields will become a war zone.

Ordinary people said they were dreading what comes next — in part because it remains unclear what Hamas wants. Spokesmen for the group have issued vague statements calling for the release of all Palestinian prisoners held by Israel.

The presence of both civilian and military hostages in Gaza greatly complicates matters.

The most high-profile former hostage was snatched in a cross border raid in 2006, the soldier Gilad Shalit, who was freed after fives years, when Israel agreed to free 1,000 Palestinian prisoners.

Hamas remained defiant. Spokesman Abdul Latif al-Qanu accused Israel of committing crimes against humanity by killing civilians and said the international community has double standards when it comes to Palestinian deaths.

“The criminal Zionist entity is trying, through the war crimes it’s committing, to rebuild its army’s spirits and its broken soldiers and to snatch the fake image after the elite Qassam’s strikes and its killing and capture of [Israel’s] army and settler herds,” he said in a statement published on the group’s Telegram channel. (BBC)

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