Mumbai has turned into a fortress as security personnel have taken their positions with a massive three dimensional security– land, air and water– put in place for the US President Barack Obama’s two day visit to the city beginning today. The Air Force One aircraft carrying President Obama and the First Lady Michelle is scheduled to land at the Chhatrapati International Airport at around12.50 pm this afternoon. The city's airspace will be closed half-an-hour before the President's arrival for all aircraft barring those carrying the US delegation.Maharashtra Chief Minister Mr. Ashok Chavan and State Protocol Minister Mr. Suresh Shetty would be receiving President Obama along with Union Minister Mr. Salman Khurshid. The Indian and American Ambassadors would also be receiving President Obama at the airport. The President and First Lady Michelle will then board a helicopter from the airport to INS Shikra, a naval air station and helicopter base in South Mumbai, from where they will travel by road to Hotel Taj.Shortly after checking in at the iconic hotel Taj, where he will be staying during his visit, President Obama will give his opening remarks to commemorate 26/11 Mumbai terror attacks. He will pay his respects to the victims and sign the guest book. The US President, who is the follower of Gandhian philosophy, will then visit the Gandhi Museum at Mani Bhawan to honour the memory of the father of the nation. Later in the evening he will attend a business summit organised by the US-India Business Council, participate in a roundtables with entrepreneurs and US CEOs and deliver a speech at Hotel Trident, another target of 26/11 attack. Tomorrow, the US President will visit the Holy Name School in Colaba and participate in Diwali celebrations with the school children. President Obama is scheduled to attend an Agricultural Exposition and the Open Government and Technology Exposition and also interact with university students at St. Xavier's college, before leaving for New Delhi tomorrow afternoon.Nearly 5,000 security personnel, including US security men, Indian Intelligence officials and elite commandos have been deployed in south Mumbai alone as all venues on the itinerary of the US President fall in this region. The Gateway of India sea front has been sanitised for three days and all the services of the boats have been suspended. The Navy and Air Force have intensified patrolling along the Mumbai coastline and its airspace during President Obama's stay.Eleven roads close to the Taj Mahal Hotel will remain closed till 4pm tomorrow. Bursting of fire crackers is also not allowed around the Taj and other areas categorised as restricted ones for the high-profile visit.