Palestinians in Gaza say Israeli bombardment has been so heavy they feel they are living their own "Nakba," the Arabic word for catastrophe that refers to the 1948 war of Israel's creation that led to their mass dispossession.

Israel on Tuesday pounded the Gaza Strip with the fiercest air strikes in its 75-year conflict with the Palestinians, leaving Gazans like Plestia Alaqad, 22, running for their lives.

"The situation is crazy - literally no place is safe. I've personally evacuated three times since yesterday," said Alaqad, who has been filming personal accounts of life under bombardment and posting them on her Instagram page.

After her apartment block was hit, she took refuge in a friend's home but then got a call it would be targeted too. After a brief stay in a hospital, where she charged her phone, she headed to another home to take shelter with journalists.

"Only yesterday I understood what my grandpa, may he rest in peace, told me about 1948 and the Nakba. When I used to hear the stories about it, I didn't understand," she said via videocall from a home in Gaza where she and others were seeking refuge from bombardment after the surprise Hamas attack on Israel.

"I'm 22 years old - and yesterday I understood the Nakba completely."

More than seven decades after the Nakba, Palestinians still lament the calamity that resulted in their displacement and blocked their dreams of statehood.

In the war surrounding Israel's founding, some 700,000 Palestinians, half the Arab population of what was British-ruled Palestine, fled or were driven from their homes, and have been denied return. Many ended up in Jordan, Lebanon and Syria as well as in Gaza, the West Bank and East Jerusalem.

Israel has already tightened its blockade of Gaza, fully banning food and fuel imports and cutting the electricity supply. Israeli Defence Minister Yoav Gallant warned that the price Gaza would pay "will change reality for generations".

Radwan Abu al-Kass, a boxing instructor and father of three boys, said his five-storey house in the al-Rimal district had been destroyed in bombardment on Monday night.

"We'd never imagine our house could become a mountain of rubble. That's all it is now," he told Reuters by phone.

Al-Kass and his children were now seeking refuge at a friend's home a few kilometres away, but feared that heavier bombardment was to come.

"This is our 1948. It's the same thing. It's another Nakba."