This concerns large parts of the major city of Rafah, which before the war had a population of over one million.
"IDF resumes fighting with great force to destroy the capacity of terrorist organizations in the area", writes spokesperson Avichay Adraee on X.
Similar warnings are usually followed by larger Israeli attacks.
Earlier in March, Israel unilaterally broke the ceasefire with terrorist-stamped Hamas in Gaza. Since then, hundreds of Palestinians have been killed, according to Hamas-controlled health authorities.