Israel has closed its borders with the West Bank over fears of an attack during celebrations marking its creation as a state 61 years ago.The total lockdown and heightened security will be lifted for humanitarian aid. Medical staff will also be able to cross the frontier, but only under coordination and with prior agreement. The restriction will remain in place until midnight on Wednesday. Palestinian militants are maintaining a ceasefire at the moment but the annual commemoration always raises tension in the region. On May 15 the Palestinians will mark the occasion in their own way. They call it “Nakba”, which means “catastrophe” in Arabic and they regard it as a time to mourn the loss of their homeland.