A UN agency aiding Palestinian refugees has demanded that the border restrictions on the Hamas-run Gaza Strip be lifted, warning that “a man-made homelessness crisis” is unfolding in the besieged enclave. The demand echoes assertions by Gaza militants who renewed the fighting on Friday, saying their key demands, including the lifting of blockade of Gaza, were not met.“We cannot rebuild it with our hands tied behind our backs. The blockade must end,” United Nations Relief and Works Agency said.