Police have tightened up security outside The Taj Mahal Palace in Mumbai. The iconic hotel in Colaba was targeted during the 26/11 Mumbai terror attack. The development comes a day after Karachi Stock Exchange terror attack. Mumbai police are on high alert also as part of enhanced anti-terror measures. Security outside the hotel and other vital installations has been increased. Reportedly, a caller from Pakistan had threatened to blow up the luxury hotel. However, there has been no confirmation from police so far on the reports.