Two Israeli air strikes on buildings in Gaza City have killed dozens of people and injured many more.

A spokesman for Gaza's civil defense said a residential block in the al-Shati area, one of Gaza's historic refugee camps, was hit several times. The other strike targeted houses in the al-Tuffah district, the government media office said.

Footage showed people carrying away the wounded and searching for survivors in the wreckage as dust filled the streets, the BBC reported. 

Earlier, the International Committee of the Red Cross said its offices in Gaza had been damaged by shelling, which killed 22 people who had sought shelter around its compound.

The Health Ministry in Gaza gave different figures, saying 25 people had been killed and 50 injured in the shelling, which it blamed on Israel.