The World Health Organization says humanitarian pauses should be respected to allow polio vaccinations in northern Gaza after six people, including four children, were injured in an attack on a medical clinic.

The WHO began the third phase of its polio vaccination campaign on Saturday. The second phase was postponed when Israel stepped up its offensive, leaving about 119,000 children unvaccinated.

The Israeli military and the Islamic group Hamas had agreed to observe a truce while the vaccinations were underway.

But Palestinian media reported that a clinic was hit by an Israeli drone strike on Saturday afternoon.

An Israeli military spokesperson said on social media that Israel is aware of the claims about injured Palestinian civilians. The official said that contrary to these claims, the Israeli military did not strike in the area at the specified time.

WHO Director-General Tedros Adhanom Ghebreyesus wrote on X on Saturday that the attack jeopardizes "the sanctity of health protection for children." He also said that these "vital humanitarian-area-specific pauses" must be "absolutely respected."