Israel's military says fired "warning shots" as crowds gathered around aid lorries but was "not aware of any casualties" from its fire.

U.S. special envoy Steve Witkoff was expected to arrive in Israel on Thursday in a bid to salvage Gaza ceasefire talks and tackle a humanitarian crisis in the Palestinian enclave, where a global hunger monitor has warned that famine was unfolding.

Shifa Hospital said the dead and wounded were among crowds massed at the Zikim Crossing, the main entry point for humanitarian aid to northern Gaza.