Mumbai has turned into a fortress to welcome the President of United States Mr. Barack Obama on Saturday. Extraordinary security measures have been taken to ensure that the American President has a safe trip. An elaborate security drill involving US secret service agents, personnel from different Indian intelligence agencies and National Security Guard commandos is being conducted in Mumbai today, which will be the first port of call for the President of United States, Mr. Barack Obama. Meanwhile, the Mumbai Fire Department has also scrutinised the fire fighting systems at all the venues where the US President is scheduled to visit.