An Israeli strike in Gaza City late Sunday night killed six journalists, according to Al-Shifa hospital, including four from Al Jazeera. The Israeli military said they targeted and killed reporter Anas Al-Sharif after accusing him of leading a Hamas cell. Mohammed Qreiqeh, another prominent Al Jazeera journalist in Gaza, was also killed in the strike, the network said. "The order to kill Anas Al-Sharif, one of Gaza's bravest journalists, along with his colleagues, is a desperate attempt to silence voices ahead of the occupation of Gaza," Al Jazeera said in a statement after the attack. In the minutes before he was killed, Al-Sharif said on social media, "If this madness does not end, Gaza will be reduced to ruins, its people's voices silenced, their faces erased — and history will remember you as silent witnesses to a genocide you chose not to stop." Al-Sharif was in a tent with other journalists near the entrance to the Al-Shifa Hospital when he was killed, according to hospital director Dr. Mohammad Abu Salmiya. The strike killed at least seven people, Salmiya said. The Israel Defense Forces (IDF) has accused Al-Sharif of leading a Hamas cell in Gaza that "advanced rocket attacks against Israeli civilians and IDF troops." The IDF had previously shown documents it claimed showed "unequivocal proof" of Al-Sharif's ties to Hamas. "The IDF had previously disclosed intelligence information and many documents found in the Gaza Strip, confirming his military affiliation to Hamas," the military said in a statement after the strike. Last month, after the IDF accused Al-Sharif of being a member of Hamas, he responded in a message on social media. "I reaffirm: I, Anas Al-Sharif, am a journalist with no political affiliations. My only mission is to report the truth from the ground — as it is, without bias," he wrote. "At a time when a deadly famine is ravaging Gaza, speaking the truth has become, in the eyes of the occupation, a threat." The Committee to Protest Journalists (CPJ) said in July they were "gravely worried" for Al-Sharif's safety and that the journalist feared for his life after he was the target of "an Israeli military smear campaign, which he believes is a precursor to his assassination." Since the beginning of the war nearly two years ago, CPJ says 186 journalists have been killed in Israeli strikes. The United Nations also called Israel's charges against Al-Sharif "online attacks and unfounded accusations." "I am deeply alarmed by repeated threats and accusations of the Israeli army against Anas Al-Sharif, the last surviving journalist of Al Jazeera in northern Gaza," said Irene Khan, the UN Special Rapporteur on freedom of expression, two weeks ago. Al-Sharif, who was married and had two children, had prepared a final message in the event of his death which was shared by his colleagues. "I urge you not to be silenced by chains, nor to be hindered by borders, and to be bridges towards the liberation of the land and its people, until the sun of dignity and freedom shines upon our occupied homeland," Al-Sharif wrote. This is a developing story and will be updated. For more CNN news and newsletters create an account atCNN.com