As fresh leads into the terror attack in the Pink city increasingly pointed to involvement of Bangladesh-based HuJI, the Centre on wednesday did not rule out the hand of a "neighbouring" country in the serial blasts that left at least 63 killed. With people of Jaipur still coming to terms with the unprecedented terror strike, Rajasthan Chief Minister Vasundhara Raje said the eight serial blasts that ripped through crowded areas and near a Hanuman temple were the handiwork of an organised "international terrorist gang" to create communal tension. The death toll rose to 63 and is likely to go up, an official said, adding nearly 130 injured persons were undegroing treatment in hospitals. As investigators sifted for clues, police said eight persons including a man injured in the blasts and a rickshaw puller are being questioned. However, no arrests have been made so far, police said.  High explosive RDX was used in the terror strike and the explosive devices were fitted with timers and planted on cycles, a modus operandi similar to the one used in last year's blasts in court premises in Uttar Pradesh in which Harkat-ul-Jehadi Islami(HUJI) was involved, police said. After visiting the site of explosions, Union Minister of State for Home Sriprakash Jaiswal said in Delhi the blasts in the walled city smacked of a "deep-rooted and very well-planned conspiracy" by a "neighbouring country" but refused to say he was pointing to Pakistan.