The Committee to Protect Journalists (CPJ) said it was “devastated by the reports”.
“Journalists are civilians and must always be protected,” it said.
The BBC was unable to verify either side’s claims, as Israel prevented international media from entering and working freely on the ground in Gaza.
Quds Today is affiliated with the Palestinian Islamic Jihad (PIJ), an armed group that participated in the Hamas-led attack on Israel on October 7, 2023. The unprecedented attack sparked the Gaza War. The TV channel is believed to receive funding from the group.
The Israeli military named the five killed as Ibrahim Jamal Ibrahim Al-Sheikh Ali; Faisal Abdullah Muhammad Abu Qamsan; Mohammed Ayad Khamis al-Ladaa; Ayman Nihad Abd Alrahman Jadi; and Fadi Ihab Muhammad Ramadan Hassouna.
It said that “intelligence from multiple sources confirmed” that all were PIJ operatives, and that a list recovered during the Gaza operation “explicitly identified four” as such.
In a statement, Quds Today said the men were “killed while performing their media and humanitarian duties.”
As of Dec. 20, at least 133 Palestinian journalists have been killed during the war, making it the deadliest conflict for journalists, according to CPJ.
The organization for freedom of the press called to account Palestinian journalists who were directly targeted by the Israeli army.
In a separate development, five people were killed in Israeli strikes on Gaza City on Wednesday.
The Palestinian Wafa news agency and the Hamas-run Gaza health ministry also said another 20 people were injured in the city’s al-Zeitoun neighborhood.
The Israeli army did not comment on the reported bombing.
Meanwhile, the father of a two-week-old Palestinian girl told the BBC how his daughter froze to death in a tent in Gaza – the third child in a week to die in similar conditions.
Mahmoud Ismail Al-Faseeh said he woke up in the bitter cold to find his daughter Sila suffering from cramps. She was rushed to the hospital, but died of hypothermia, the head of pediatrics at Nasser Hospital in Khan Younis told the Associated Press news agency.
The family took refuge in the al-Mawasi area of the Gaza Strip, a strip of land designated by the Israel Defense Forces (IDF) as a humanitarian zone but hit by airstrikes.
Ahmed al-Farra, head of paediatrics, said two other babies – one three days old and the other one month old – were brought in in the last 48 hours after dying of hypothermia.
Hopes of progress towards a ceasefire have begun to recede in recent days, with Hamas and Israel accusing each other.
Hamas accused the Israeli government of imposing “new conditions” which it said were delaying the agreement.
Israeli Prime Minister Benjamin Netanyahu said the group was rejecting agreements already reached on a possible ceasefire.
The latest statements mark a noticeable change in tone on both sides after upbeat signals.
The Israeli military launched airstrikes and a ground offensive in the Gaza Strip in response to last year’s attack by Hamas. About 1,200 people were killed in the attack, and another 251 were returned to Gaza as hostages.
More than 45,000 Palestinians have been killed in the Israeli offensive, according to Gaza’s health ministry. According to the UN, almost two million people – 90% of the population – have been displaced.
Additional reporting by Jaroslav Lukiv.
