Angered by living in tents for two winters and now baking in the midst of an intense heat wave, the squatters took over the unfinished apartment house and have already resisted one police effort to evict them.

"The heat and cold hurt our children. Where are you?" read a banner pasted on the wall of the building, in the first overt move against government property since Hamas took power in 2007.

Bassam Jamil, one of the squatters, said 43 families had moved into the building, which was still under construction in Jabalya in the northern Gaza Strip. It belongs to the Hamas-run housing ministry.

"We have lost faith that anyone will rebuild our homes. We have taken shelter in the building from the heat in the tents we've been living in," Jamil said.

Thousands of homes and factories were destroyed by Israeli bombing and shelling in a three-week war in Dec-Jan 2008-09 against Hamas.

Earlier this week, Hamas police tried to evict the families but were confronted with resistance by women and children.

The building has 44 unfinished apartments. The squatters say they are still better than tents. They have fitted their own doors and are now asking city authorities to turn on electricity and water.