GAZA, JERUSALEM and LONDON -- Israel on Tuesday issued an order calling for residents of Gaza City to evacuate, saying the Israeli military will operate "with great force" within the city.

"Staying in the city is extremely dangerous," Avichay Adraee, a spokesperson for the Israel Defense Forces, said on social media.

The order and warnings followed an approval by Prime Minister Benjamin Netanyahu's government of a plan to seize Gaza City, the largest city in the under-siege enclave. Israel began ground operations within the city about a week ago.

Israeli officials said the planned seizure is part of its military objective to eliminate Hamas, the terrorist organization that it's been fighting in Gaza since October 2023.

Despite the severe situation and evacuation warnings, there are still a significant number of residents who remain in the city who have cited different reasons for staying, including not being able to afford the costs of evacuation and transportation.

Others have said they've stayed because they've heard there's a severe shortage of space for tents in the humanitarian zone -- or that they don't know if they would be safe after an evacuation.

Adraee said residents of Gaza City and "all its neighorhoods" should evacuate immediately. They should travel south toward Al-Mawasi, a coastal area that's been designated as a humanitarian zone, he said.

The evacuation order followed a warning issued on Monday by Netanyahu. In a video message posted on Telegram, he spoke directly to the residents of the city.

"Listen carefully: You have been warned," Netanyahu said. "Leave now."