Israeli prime minister Benjamin Netanyahu has ordered the military to start a ground operation in Gaza, his office has announced. The new phase of Operation Protective Edge has already resulted in 23 civilian casualties and one of an Israeli soldier.

"The prime minister and defence minister have instructed the IDF to begin a ground operation tonight in order to hit the terror tunnels from Gaza into Israel," the statement said.

The ground phase of Operation Protective Edge has claimed more than 20 lives overnight. And barely a day into the fighting, Netanyahu is announcing a significant expansion of the ground operation.

"My instructions ... are to prepare for the possibility of significantly widening the ground operation, and the military is preparing accordingly," he said in the run-up to a meeting of his cabinet ministers, according to Reuters.

FOLLOW UPDATES on Israel's military offensive in Gaza

Israel had originally organized about 48,000 reserve soldiers for the operation, but on Thursday another 18,000 were called up, as reported by the Associated Press. It's unclear how many are actually involved in the ongoing ground offensive.

BREAKING NEWS: A large IDF force has just launched a ground operation in the Gaza Strip. A new phase of Operation Protective Edge has begun. — IDF (@IDFSpokesperson) July 17, 2014

IDF artillery fire and airstrikes have killed seven Palestinians and wounded dozens more across the Gaza Strip, according to Haaretz. Meanwhile, the Palestinian Health Ministry is dismissing previous reports stating the IDF is utilizing poison gas, saying those allegations “are meant to confuse civilians.”

In the meantime, the Jerusalem Post is reporting that Hamas continues to launch rockets in the direction of southern and central Israel. Haaretz added that the Iron Dome has successfully intercepted three rockets over Ashdod, but more rocket fire should be expected.

At least five people have been killed as a result of Israeli tank fire, according to the Ma'an News Agency. Journalist Hala Jaber is reporting that a five-month old baby was killed by shrapnel. Other people have been injured and are being taken to hospitals for treatment.

Gaza's Al-Wafa hospital has also come under fire from tanks. The facility houses 14 patients, some of which are paralyzed or in comatose states. Several people, including nurses, have been injured. Workers have been told to evacuate the building, but they say that moving the patients is "almost impossible."

As the operation intensifies, the Washington Post is reporting the Qassam Brigades – Hamas' military wing – are engaged in a confrontation with Israeli forces near the Erez crossing, which acts as a passageway between Israel and Gaza. A tweet by the IDF also mentioned that an anti-tank missile had caused damage to one of Israel's heavy bulldozers in southern Gaza, but no injuries were reported.

As the offensive began, Israel's chief military spokesman Brig. Gen. Motti Almoz urged residents in Gaza to evacuate areas in which the military is operating, since it is doing so with "very great force."

5 month old baby boy Fares Jumaa al-Mahmoom killed tonight and 8 others injured taken to Abu Yussuf Al-Najar hospital in #Gaza. — Hala Jaber (@HalaJaber) July 17, 2014

According to the IDF statement, the goal is to target Hamas tunnels that “enable terrorists to infiltrate Israel and carry out attacks.”

"We are now continuing with the ground forces to strike terrorist infrastructure, Hamas infrastructure, in multiple areas throughout the Gaza Strip," army spokesman Lieutenant-Colonel Peter Lerner told reporters.

"Following 10 days of Hamas attacks by land, air and sea, and after repeated rejections of offers to deescalate the situation, the Israel Defence Forces (army) has initiated a ground operation within the Gaza Strip," the IDF said in a statement, according to an AFP report.

The IDF also accused Hamas of using civilian deaths to paint Israel’s actions in a negative light.

"In the face of Hamas' tactics to leverage civilian casualties in pursuit of its terrorist goals, the IDF will continue in its unprecedented efforts to limit civilian harm," it said.

Hamas, meanwhile, said Israel's move is "foolish" and will have "dreadful consequences."

Speaking with CNN, Hamas spokesman Fawzi Barhoum said, “the beginning of the Israeli ground invasion of Gaza is a dangerous step with unknown consequences. Israel will pay a heavy price for it.”

Witnesses and Gaza residents reported heavy artillery and naval shelling along the Gaza border.

Israel’s latest ground operation comes after attempts to broker a cease-fire with Hamas failed to take hold. The last 10 days have seen both sides exchange rocket fire, resulting in the deaths of more than 220 Palestinians and one Israeli, with some attacks coming under intense scrutiny. Recently, four Palestinian children were killed by an Israeli airstrike while they were playing on a beach in Gaza.

Overall, Israel has struck more than 2,000 targets in Gaza, while Hamas has fired almost 1,500 rockets towards Israel.

Although both Israel and Hamas agreed to observe a brief suspension of hostilities following a request by the United Nations, reports indicated on Wednesday that Israel was considering sending boots on the ground in order to remove rockets and other weapons used by Hamas.

"The IDF's objective as defined by the Israeli government is to establish a reality in which Israeli residents can live in safety and security without continued indiscriminate terror, while striking a significant blow to Hamas's terror infrastructure,” the army said in its statement.

The last time Israel launched an extensive ground offensive in Gaza was back in January 2009, following an armed conflict that began the month prior in December. That offensive, known as Operation Cast Lead, began on January 3 and was tasked with a similar objective: to secure areas from which militants were launching rockets. The entire conflict – which ran from December 27, 2008 to January 18, 2009 –resulted in the deaths of up to 1,417 Palestinians and 13 Israelis.