After arresting a top Naxal leader, investigators are on the trail of some Maoist leaders believed to be hiding in Delhi, police sources said on Tuesday.Kobad Gandhi, 63, a politburo member of the Communist Party of India - Maoist, was arrested by the Special Cell of Delhi police from Bikhaji Cama Place on Sunday night, following an input received from intelligence agencies."We believe that this arrest will lead to more arrests of Naxal leaders," said a police official.