Israel's army is now operating in the centre of the Palestinian city of Rafah in the southern Gaza Strip, the military said on Friday.
Israeli troops had discovered rocket launchers, tunnels and Hamas weapons there, the army said.
Although eyewitnesses had seen tanks in the centre of the city earlier in the week, there had been no confirmation that ground troops were deployed there until now.
The operation in Rafah has been sharply criticized internationally, including by Israel's closest allies.
Asked in March whether invading Rafah would be a "red line," US President Joe Biden told broadcaster MSNBC: "It is a red line." Speaking to CNN earlier this month, he threatened to restrict the US' supply of weapons to Israel if the Jewish state invaded Rafah.
A week ago, the International Court of Justice (ICJ) in the Hague ordered Israel to end the military operation in Rafah immediately.
