GENEVA (Reuters) - The United Nations Palestinian refugee agency, UNRWA, said on Monday that reports of attacks on families seeking shelter in Rafah in the southern tip of the Gaza Strip were "horrifying".

"Information coming out of Rafah about further attacks on families seeking shelter is horrifying," UNRWA wrote on X.

"There are reports of mass casualties including children and women among those killed. Gaza is hell on earth. Images from last night are yet another testament to that."

Palestinian health and civil emergency service officials said on Sunday Israeli air strikes killed at least 35 Palestinians and wounded dozens in an area in the southern Gaza Strip city of Rafah designated for the displaced.

The Israeli military said its air force struck a Hamas compound in Rafah, and that the incident was under review.

(Reporting by Gabrielle Tétrault-Farber; Editing by Alison Williams)