KARACHI - The modus operandi of the seven blasts, that rocked the city on 7th July, has confused the concerned authorities as they could not so far find any clue to the mysterious explosions. Police have arrested a number of suspects to interrogate but failed to ascertain the real motive and reasons behind the blasts. Source privy to the matter told, on condition of anonymity, the case is not as simple as it appears because investigators are still unsuccessful to find any tangible evidence. He added that culprits have used similar tactics in the blasts they had used at Quaidabad. The source further pointed out that police had recovered a car and motorcycle used in series of bombings in Karachi. The suspected car had been stolen from Gulberg police limits on the same day therefore it would be difficult to identify the culprits through the owner of the vehicle. The motorbike involved in the terrorist activity had lost its identification as the culprits had earlier erased its engine and chasis numbers and also fixed fake registration at the time of crime. The investigators are drawing sketches of the culprits on eyewitnesses' accounts and recorded the statements of victims. Another source in police department told that it would be difficult for the investigators to rule out the possibility of involvement of the radical elements because numerous cases had been reported in the past in which militants have used similar tactics. He citied that a senior police official of the investigating team had busted a group of militants belonging to a splinter group under the name of United Muslim Army (UMA).  The operatives of this group had been arrested and most of them were still detained. The source further said that "to get maximum media attention and create fear among the masses within minimum resources" is the primary objective of any terrorist organisation.