GAZA - At least six Palestinians were killed and 40 others injured in an Israeli airstrike on the European Hospital in the southern Gazan city of Khan Younis, Gaza-based health authorities said in a statement on Tuesday.

The Palestinian official news agency WAFA reported that 16 people had died in the strike, while other media outlets cited rescuers who put the death toll at 28.

Palestinian security sources said the hospital was hit by at least six missiles. Videos circulating on social media showed significant damage to the facility.

The Israel Defense Forces (IDF) said in a statement that it had carried out a "precise strike" in coordination with the Israel Security Agency, targeting Hamas operatives located beneath the hospital.

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According to the IDF, the strike was aimed at an underground Hamas command and control center. The military accused Hamas of continuing to use hospitals in Gaza to conceal militant infrastructure.

Israeli state broadcaster Kan and other media outlets reported that the strike targeted Hamas figure Mohammed Sinwar. It remained unclear whether he was among the casualties. Sinwar is the younger brother of former Hamas leader Yahya Sinwar, who was killed by Israeli forces in southern Gaza in October last year.

Hamas, in a statement issued Tuesday, rejected the Israeli claims, calling them "lies and attempts to mislead international public opinion". The group accused Israel of exploiting such allegations to justify attacks on Gaza's healthcare system and to "terrorise civilians". The statement did not address whether Mohammed Sinwar was present at the site.

Al-Quds Brigades, the armed wing of the Islamic Jihad movement, said it had launched rocket attacks on Israeli cities in response to Israeli airstrikes on the European Hospital.

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"We attacked Ashdod, Ashkelon, Sderot and Israeli settlements adjacent to Gaza with rocket barrages in response to the Israeli massacres against our Palestinian people," al-Quds Brigades said in a press statement on Tuesday.

A source in the movement said the attack aimed to demonstrate "the resistance's ability to respond decisively to Israeli attacks".

Israeli media outlets, reported that sirens sounded in several cities and towns in southern Israel, including Ashdod, Ashkelon, and Sderot.

Avichay Adraee, the Israeli military spokesperson, said in a statement that two rockets fired from the Gaza Strip were intercepted, while a third landed in an open area, without causing casualties or significant material damage.

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Following the rocket attack, the IDF on Tuesday night ordered residents of the Jabalia city and refugee camp, and other surrounding neighborhoods in the central Gaza Strip, to immediately evacuate ahead of an Israeli strike.

The residents were instructed to relocate immediately to the shelter centers in Gaza City.