Israel is stepping up its ground and air offensive against Hamas in the Gaza Strip. The Israeli military says its troops have now completely encircled Gaza City.

Following Thursday's announcement, Israel carried out intense bombings of northern Gaza. Footage showed flares lighting up the night sky, while missiles rained down amid loud explosions.

CNN said the air raid continued for more than 30 minutes. It said a smoke screen covered the ground, "suggesting the possible movement of Israeli troops in the area."

Meanwhile, Hamas is not letting up its resistance. The Islamic group has released a video of one of its fighters apparently emerging from an underground tunnel. The fighter was seen placing an explosive device on an Israeli tank, and then retreating to detonate what appeared to be a rocket launcher.

The hostilities that began with Hamas's surprise attack on October 7 has led to 9,061 deaths in Gaza. At least 1,400 people have been killed in Israel.

Israel is also being attacked from the north, by the Lebanese militant group Hezbollah. Rockets hit the northern Israeli city of Kiryat Shmona on Thursday, wounding two people.

Hezbollah leader Sayyed Hassan Nasrallah is due to deliver a speech on Friday, amid mounting concerns over the possible escalation of fighting on two fronts-- along Israel's border with Lebanon in the north, and the Gaza Strip in the south.

US Secretary of State Antony Blinken is due to arrive in Israel on Friday. He is expected to discuss how to minimize harm to civilians and allow more deliveries of humanitarian aid.