Israeli tanks blocked the main road to Gaza City on Thursday, preventing those who have left the besieged city from returning, and Defence Minister Israel Katz said it was now the last chance for hundreds of thousands of people still inside to escape. Israel has told the entire million-strong population of Gaza City to head south as it mounts one of the biggest offensives of the war this month, vowing to root out Hamas fighters in what it says are their last bastions in Gaza's biggest urban area. Residents told Reuters that tanks had set up sand barriers on the main road south out of Gaza City. People were being allowed out, but those who had left in search of...