GAZA/JERUSALEM - Israel heavily bombarded Gaza City early Tuesday, according to multiple media reports.

Axios, a US media outlet, reported that the Israeli military launched a ground offensive on Monday to occupy Gaza City, citing Israeli officials. Israeli newspaper The Jerusalem Post confirmed that the Israel Defense Forces (IDF)'s invasion of Gaza City erupted late Monday night.

According to the Times of Israel, the IDF has been gradually expanding airstrikes in and around the city in recent days, but has not dispatched ground troops into the densely populated northern city.

Local sources and eyewitnesses in Gaza denied any Israeli tank incursion into Gaza City. There was no sighting yet of penetration or movement of Israeli tanks into the depths of the city, said residents in Gaza City. But they confirmed intense air strikes and drone bombings in most parts of Gaza City.

Following air strikes and bombardment in Gaza City, Israeli Defense Minister Israel Katz said Tuesday morning in a statement that "Gaza is burning."

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Katz said that the IDF is striking the "terror infrastructure" with an iron fist and fighting to create the conditions for the release of the hostages and the defeat of Hamas.

"We will not relent and we will not back down, until the mission is completed," Katz added.

The Palestinian official news agency WAFA reported early Tuesday that the Israeli army has intensified its raids on Gaza City since Monday night. Citing local sources, WAFA said that Israeli warplanes were launching continuous raids on the city, almost without stopping.

In recent weeks, some 300,000 Palestinians have fled Gaza City, home to nearly 1 million people, reported Israel's Army Radio.

On Monday, US Secretary of State Marco Rubio vowed Washington's "unwavering support" to Israel in its offensive in Gaza and called for Hamas' eradication during his visit to the country.

"The people of Gaza deserve a better future, but that future cannot begin until Hamas is eliminated," Rubio told reporters at a press conference alongside Israeli Prime Minister Benjamin Netanyahu in Jerusalem.

In early August, Israel's Security Cabinet approved a plan to take over Gaza City. Israel's military spokesperson Effie Defrin said earlier this month that Israeli forces control about 40 percent of Gaza City and will "expand and intensify" the offensive in the coming days to seize the enclave's largest urban center.