The lone surviving gunman of the 2008 Mumbai attacks could be executed this year if he does not appeal his death sentence, a senior Indian government official said on Tuesday. Mohammed Ajmal Amir Kasab, 22, was found guilty of waging war on India, mass murder, conspiracy and terrorism offences last week over the assault, which left 166 people dead and more than 300 injured. Home secretary G.K. Pillai said Kasab's fate depended on whether the Pakistani national challenged the sentence through the higher courts and filed an appeal for clemency to the country's president. If he doesn't file any appeal anywhere I think the chances of him getting hanged this year are quite high, he told the CNN-IBN news channel in an interview.