Israeli forces have launched a ground offensive in the Gaza Strip, the country's military said.
The operation came after 10 days of intense fighting between Israel and the Islamic militant organisation Hamas.
The army said the offensive is meant to strike a "significant blow to Hamas' terror infrastructure."
It did not say how many troops were involved or provide other details.
Israeli Prime Minister Benjamin Netanyahu's office said he instructed the army to go ahead after Hamas rejected an Egyptian cease-fire plan earlier in the week and after Hamas militants tried to infiltrate into Israel through a tunnel from Gaza earlier Thursday.
"In light of the despicable and relentless aggression by Hamas and the dangerous infiltration into Israel, Israel is obliged to protect its citizens," the statement said.
The Israeli military says Gaza militants have fired more than 1,300 rockets into Israel, and Palestinian health officials say 233 Palestinians have been killed in Israeli air and naval strikes. One Israeli civilian has been killed by fire from Gaza.
A statement from the Israeli military said the operation will include "infantry, armoured corps, engineer corps, artillery and intelligence combined with aerial and naval support."
Before dawn on Thursday, about a dozen Palestinian fighters tunnelled under the border, emerging near an Israeli community. At least one was killed when Israeli aircraft bombed the group, the military said.
