Hamas gunmen launched an unprecedented assault on Israel from the Gaza Strip on 7 October, killing more than 1,400 people and taking 242 hostages.
Since then, Israel has been carrying out retaliatory strikes on Gaza, in which more than 9,000 people have been killed, according to the Hamas-run health ministry.
Israel has also sent troops and tanks into the territory.
What is Israel doing in Gaza?
Israel’s Prime Minister, Benjamin Netanyahu, said on Monday that he had set “the clear goal of destroying Hamas’s military and governing capabilities”, as well as freeing the hostages.
He also rejected calls for a ceasefire.
The Israeli Defense Forces (IDF) says it has broken through Hamas’s front lines of defence in northern Gaza, and an Israeli commander said its troops were at “the gates of Gaza City”.
On Thursday morning the BBC’s reporter in the Gaza Strip, Rushdi Abualouf, said there were five different battles under way in the north and around Gaza City.
He said the biggest was in the north-west of the strip, where “very few” people remain.
The IDF claimed to have killed “dozens” of Hamas fighters in clashes overnight into Thursday.
It said 17 of its own troops have died during the ground offensive in Gaza, and that a total of 330 soldiers have been killed since 7 October.
Israel’s Minister of Defence, Yoav Gallant, said 10,000 munitions have been dropped on Gaza City alone since the conflict began.
The Hamas-run Ministry of Health in Gaza says that 1,000 people are dead, wounded or missing following Israeli air strikes on Jabalia, in northern Gaza, on Tuesday and Wednesday.
Previously, it said 195 people had been killed.
Several residential buildings were destroyed in the strikes.
The Israeli military said it had killed a senior Hamas commander and dozens of fighters.
Heavy shelling has also been continuing around the Al-Quds Hospital in Gaza City, according to the Palestinian Red Crescent.
Around 14,000 people are thought to be sheltering there.
The Palestinian Red Crescent said the Israeli military told staff to evacuate on Sunday ahead of strikes, but that it was impossible to move the hundreds of patients who are being treated there.
The IDF has tens of thousands of soldiers, along with tanks and artillery, both along Gaza’s borders and within the territory. It has activated some 300,000 reservists alongside its standing force of 160,000.
Hamas is thought to have about 25,000 members in its military wing. It also has a network of underground tunnels across Gaza, connecting its command centres, which it has said stretch for 500km (310 miles).