TEL AVIV—Israel’s military said it has begun ground operations against Hamas in Gaza, escalating its offensive against the militant group.

Lt. Col. Jonathan Conricus, an Israeli military spokesman, said ground and air forces are striking targets in Gaza from the Israeli side of the border, including tanks and artillery. He initially said Israeli troops had entered the Gaza Strip but later retracted that statement.

“There are ground forces currently deployed along the border area and they are engaging and attacking the Gaza Strip from there,” said Col. Conricus.

Israel’s military didn’t give more details about the operation, but some 3,000 to 4,000 troops have been amassed on the border in recent days, military officials have said. Those figures suggest a more limited operation because a full-scale invasion would require many more troops.

It isn’t immediately clear how big the ground operation is or what its aims are, but if troops actually cross into Gaza it would be the first time since the 2014 war that Israeli troops have entered Gaza to fight.