New Delhi, Nov 28 : A police van carrying Aaftab Amin Poonawalla, who is accused of the ghastly murder of his live-in partner Shraddha Walkar in Delhi's Mehrauli area, was attacked by unidentified people armed with swords and sticks when he was being taken back to Tihar jail after a polygraph test at the Forensic Science Laboratory (FSL) in Rohini. However, the van exited safely and the people who were also pelting stones were stopped by the police. Further details are awaited. Meanwhile, the FSL officials conducted the polygraph test on Aaftab for nearly seven hours on Monday. Sanjeev Gupta, Deputy Director, FSL, said the polygraph test is likely to continue further. "The process for narco test will also start soon," said the official. According to sources, Aaftab was asked around 60 questions during the session on Monday. As per a source, a polygraph and narco tests are imperative in this case, as Aaftab, during questioning, was deceptive in nature and also tried to mislead the interrogators. Aaftab was arrested on November 12 for the murder he committed on May 18. /IANS