Nearly four years after the Mumbai terror attack, Ajmal Kasab, the sole surviving Pakistani gunman, was hanged to death at the Yerawada central prison here this morning in an operation shrouded in secrecy. The 25-year old Kasab was hanged early on Wednesday, Maharashtra Home Minister R R Patil said in Mumbai shortly after the hanging. Pakistan government was kept informed about the execution, Press Trust of India (PTI) reported. The 60-hour siege of Mumbai began on 26 November 2008. Attacks on the railway station, luxury hotels and a Jewish cultural centre claimed 166 lives. Nine gunmen were also killed. Kasab and an accomplice carried out the assault on the main railway station, killing 52 people.