More than 30 Palestinian NGOs released a statement on Sunday denouncing a "premature" Human Rights Watch (HRW) report that suggested the Al-Ahli 'Baptist' Hospital explosion was likely caused by a misfired rocket similar to those used by Palestinian groups.
The statement described the HRW report as inconclusive and potentially misleading due to its reliance on limited evidence and lack of access to the site.
It also criticised the report's methodology, which depended on indirect evidence such as the size of the crater and the type of "splatter" pattern left by the impact of the strike.
The statement also questioned HRW's attempt to balance its findings with a response from Hamas, despite Israel blaming another group - Palestinian Islamic Jihad (PIJ) - for the incident.
"Given the dire conditions on the ground, Gaza currently lacks any semblance of a civil authority - let alone one capable of engaging with such requests for disclosure of evidence or information," reads the statement.
At least 471 people were killed and 342 injured in the strike on the hospital on 17 October, which has widely been blamed on Israel. Many of those killed had been displaced people camped out in the hospital's grounds.
"Evidence" presented by Israel to pin blame for the attack on Palestinian groups has largely been disproven, while rights groups and health workers have shown proof of repeated targeting of Gaza's health facilities.
Human rights and civil society groups that signed the statement against the HRW report called for an independent investigation into the massacre.
The Palestinian groups said the HRW investigation largely overlooked the likelihood of Israel using a new type of munition.
The report released by Human Rights Watch on Sunday stated that its findings were based on an analysis of photos and videos, satellite imagery, and interviews with witnesses and experts.
"The explosion that killed and injured many civilians at Al-Ahli Arab Hospital in Gaza on October 17, 2023, resulted from an apparent rocket-propelled munition, such as those commonly used by Palestinian armed groups," HRW said.
The report also questioned the number of casualties reported by Gaza's health ministry, pointing out discrepancies between the reported figures and the visible damage on site.
Israel's military offensive and related power shortages have put 26 of Gaza's 35 hospitals out of action, according to Gaza's health ministry.
In the somewhat less affected southern region of Gaza, only nine hospitals and 18 primary healthcare centres are operational, and their capacity is severely constrained.
They struggle with a critical shortage of medical supplies, barely managing to perform essential and life-saving surgeries and provide care.
The World Health Organisation (WHO) has documented 164 incidents of 'attacks on healthcare' in Gaza since 7 October.
Al-Shifa Hospital director Mohammad Abu Selmeyah - currently detained by the Israeli army - had previously said that Israel is "targeting hospitals in Gaza City in its military campaign".