Court officials in India say the only surviving gunman from the deadly 2008 Mumbai terrorist attacks has filed an appeal to the Supreme Court to have his death sentence overturned.

A Mumbai court convicted Pakistani national Mohammed Ajmal Kasab last year on a number of charges, including murder, waging war against India, and terrorism, and sentenced him to death.

Kasab's death sentence was confirmed by Maharashtra state's high court in February.

Kasab was one of 10 young Pakistanis who attacked luxury hotels, a Jewish center and a busy train station in India's financial hub in November of 2008. The three-day siege killed 166 people.

Meanwhile, police continue to investigate the triple bomb blasts that hit Mumbai earlier this month. No one has claimed responsibility for the July 13 attack. On Thursday, another person wounded in the explosions died at a hospital, bringing the death toll to at least 25.