Gaza City - Ahmed Abu Saif struggles to maintain a straight face as he looks at the amorphous pile of rubble of what used to be a five-storey building he owned.

The structure is one of the several civilian sites that have been flattened over the past 24 hours in Gaza as Israeli jets pounded the besieged and densely-populated coastal enclave amid rising tensions.

"I expected to see my building burned to the ground one day, simply because I live in Gaza," the 64-year-old owner of the al-Rahma building, told Al Jazeera on Tuesday.

"Everything in Gaza is a target, regardless of who it belongs to," he said.

"The occupation does not differentiate. To them, a Palestinian is a Palestinian."

On Tuesday, the armed wing of Hamas, the group that administers the Gaza Strip, warned it would increase attacks and fire rockets at the Israeli towns of Ashdod and Beersheba if Israel continues to carry out air raids on civilian buildings.

The statement by al-Qassam Brigades was released hours after a rocket from Gaza killed an Israeli man in the coastal town of Ashkelon.