The warning from a very senior Israeli official on Wednesday came hours after US President George Bush backed Israeli Prime Minister Arial Sharon's plans to withdraw from the Gaza.
"If the Palestinians launch attacks from Gaza after the withdrawal, there will be a very serious response," the official said.
"Be very careful. Don't even dare to carry out terror attacks because our response will be very strong," he said. "It is Israel's duty to act against terrorist organisations."
"Just like we did with Shaikh Yasin, we will go back and do it again and hurt the terrorist infrastructure," the official added.
Israeli occupation soldiers, meanwhile, have raided a refugee camp on the southern edge of the Gaza Strip.
Witnesses said about 40 armoured vehicles backed by two helicopters were brought into the Rafah area, shortly after US President George Bush pledged support for an Israeli withdrawal from Gaza.
An Israeli military source said the troops were there to identify and destroy tunnels allegedly used to smuggle weapons into Gaza from neighbouring Egypt.
Palestinian fighters detonated an explosive to try to keep the soldiers away and Israeli troops returned fire. There were no immediate reports of casualties.
Israel has carried out frequent raids in Rafah and its troops have demolished scores of homes, besides killing many Palestinians.