GAZA/JERUSALEM - The Israeli army conducted on Tuesday intense airstrikes on the northern and central Gaza Strip, marking the most violent escalation since the ceasefire, according to local sources and eyewitnesses.

Palestinian medical and security sources told Xinhua that Israeli warplanes launched raids of unprecedented scale, triggering successive explosions in several areas of northern and central Gaza.

The sources said that the Israeli army has killed over 200 Palestinians in the coastal enclave.

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In an initial statement, the Palestinian Civil Defense said that Israeli aircraft targeted homes, mosques, schools and shelters, resulting in significant casualties.

"Our crews are facing great difficulties due to the size and number of targets being struck simultaneously," the civil defense added.

Israeli Prime Minister Benjamin Netanyahu's office announced early Tuesday that Netanyahu and the country's Defense Minister Israel Katz had ordered the military to "operate against Hamas with increasingly powerful military force."

According to the statement, the move followed what it described as Hamas's "repeated refusal to release hostages" and rejection of proposals presented by US envoy Steve Witkoff and other mediators.

The Israel Defense Forces (IDF) was conducting "extensive strikes" on Hamas targets, it said.

The statement added that the strikes are being carried out under an operational plan presented by the IDF over the weekend and approved by the political leadership.

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Katz warned in a separate statement that if Hamas does not release all hostages, "the gates of hell will open in Gaza," and Hamas will encounter the Israeli military "with an intensity they have never known before."

Israel's state-owned Army Radio said that the move indicated the fragile ceasefire between Israel and Hamas, which took effect on Jan. 19, "has collapsed."