Israel’s military said it killed a Hamas cell leader posing as an Al Jazeera journalist in a Gaza airstrike on Sunday, but rights advocates said he had been targeted for his frontline reporting on the Gaza war and Israel’s claim lacked evidence.

Anas Al Sharif, 28, was among a group of four Al Jazeera journalists and an assistant who died in a strike on a tent near Shifa Hospital in eastern Gaza City, Gaza officials and Al Jazeera said. An official at the hospital said two other people were also killed in the strike.

Al Sharif was the head of a Hamas cell and “was responsible for advancing rocket attacks against Israeli civilians and IDF (Israeli) troops,” the Israeli military said in a statement, citing intelligence and documents found in Gaza as evidence.

Journalists’ groups and Al Jazeera denounced the killings. The other journalists killed were Mohammed Qreiqeh, Ibrahim Zaher and Mohammed Noufal, Al Jazeera said.

A press freedom group and a UN expert previously warned that Al Sharif’s life was in danger due to his reporting from Gaza. U.N. Special Rapporteur Irene Khan said last month that Israel’s claims against him were unsubstantiated.

Al Jazeera said Al Sharif had left a social media message to be posted in the event of his death that read, “...I never hesitated to convey the truth as it is, without distortion or misrepresentation, hoping that God would witness those who remained silent.”

In a statement, the Committee to Protect Journalists, which in July urged the international community to protect Al Sharif, said Israel had failed to provide any evidence to back up its allegations against him.

“Israel’s pattern of labeling journalists as militants without providing credible evidence raises serious questions about its intent and respect for press freedom,” said Sara Qudah, CPJ’s director for the Middle East and North Africa.

Al Sharif, whose X account showed more than 500,000 followers, posted on the platform minutes before his death that Israel had been intensely bombarding Gaza City for more than two hours.

Calling Al Sharif “one of Gaza’s bravest journalists,” Al Jazeera said the attack “is a desperate attempt to silence voices in anticipation of the occupation of Gaza.”

Palestinian militant group Hamas, which runs Gaza, said the killing may signal the start of an Israeli offensive. “The assassination of journalists and the intimidation of those who remain paves the way for a major crime that the occupation is planning to commit in Gaza City,” Hamas said in a statement.

Israeli Prime Minister Benjamin Netanyahu has said he would launch a new offensive to dismantle Hamas strongholds in Gaza, where a hunger crisis is escalating after 22 months of war.

“Anas Al Sharif and his colleagues were among the last remaining voices in Gaza conveying the tragic reality to the world,” Al Jazeera said.

The Hamas-run Gaza government media office said 237 journalists have been killed since the war started on October 7, 2023. The Committee to Protect Journalists said at least 186 journalists have been killed in the Gaza conflict.