Hours after Israel withdrew its troops from Gaza City in the opening stage of a US-brokered ceasefire, tens of thousands of Palestinians trudged back to sift through bombed out buildings overseen by Hamas security operatives.The Hamas interior ministry said in a statement on Friday that its police force would deploy across the territory. By Saturday, masked men wearing caps labelled “Internal Security” and armed with Kalashnikov assault rifles were inspecting car trunks and reasserting their authority, according to witnesses and images posted on social media and filmed by Al Jazeera. It was an early sign that Israel’s goal of removing the Islamist group from power – and US President Donald Trump’s aim of a lasting peace – won’t be simple. Nor will the task of rebuilding.“Everybody I know has lost their house,” said Mahmoud Faraj, who left Gaza City with his family last month when Israeli troops took over. Speaking by phone, he said, “My family is staying in the south of Gaza in their displacement site because there is no home to return to.”The scale of destruction in Gaza City may be slightly less than in the southern part of the coastal enclave but is still massive. Most high-rise buildings have been levelled – Israel says they contained Hamas intelligence infrastructure – and some streets are unrecognisable.Hamas has agreed to free 20 living hostages – and hand over the remains of 28 others – by Monday, when Trump arrives in Jerusalem to address the Parliament before heading to Egypt for a signing ceremony.