Israel has carried out overnight air strikes against Gaza's security headquarters and police stations. It is the heaviest bombardment since operations began on 8 July, BBC reported on Sunday.
At least 159 Palestinians have died in the air strikes, Gaza officials say.
The Israeli air strikes destroyed most of the security headquarters and police stations run by Hamas Islamist militants.
The homes adjacent to the security compound suffered extensive damage, as the headquarters are located in the densely populated neighbourhood of Tel al-Hawa in south Gaza.
Israel said its troops had carried out a brief raid against a rocket-launching site in the coastal territory.
Palestinian militants fired about 90 rockets from the Gaza Strip into its territory on Saturday, Israel claimed.
The UN Security Council has called for a ceasefire and peace talks.
It is the first time since Israel's offensive began that they have issued a statement, with members previously divided on their response.