Floral tributes were today paid to martyrs of the 2008 Mumbai terror attacks on the fourth anniversary of the strike with Union ministers Sushil Kumar Shinde and Sharad Pawar laying wreaths at the police memorial in South Mumbai.

Maharashtra Governor K Sankara Narayanan, Chief Minister Prithviraj Chavan, Home Minister R R Patil, Mumbai Police Commissioner Satyapal Singh and family members of the victims and brave-hearts, also paid floral tributes to those killed in the November 26, 2008 siege.

Lone surviving Pakistani terrorist Ajmal Amir Kasab, who was nabbed after the carnage was hanged in Pune's Yerawada Jail on November 21.

Security has been stepped up in the metropolis, after Tehreek-i-Taliban Pakistan spokesman Ehsanullah Ehsan warned of mounting attacks “in India and anywhere” to avenge Kasab's hanging.

Vital establishments, including airports and the Bhabha Atomic Research Centre are also under tight vigil after the threat.