Maharashtra Chief Minister Prithviraj said the investigations had not yet led to any arrests though the police had got some clues regarding the killing of 69-year-old Dabholkar on Tuesday.
"There is a progress in the investigation and police have got certain clues. But they have not yet led to any arrests in the case," he told reporters.
Chavan said apart from nabbing the actual killers of Dabholkar, it was also important to find out the elements behind the dastardly attack.
Police had formed 19 teams to crack the case and the progress of investigations was reviewed by Maharashtra Director General of Police Sanjeev Dayal, he added. A sketch of one of the two alleged assailants were also released by police.
"This (the murder) is a very serious incident in which the assailants tried to silence the voice of an independent thinker," the chief minister added.
Dabholkar, who was in the forefront of anti-superstition movement in the state, was shot dead by two motorcycle borne unidentified assailants at around 7.15 am, when he was out for a morning walk on the Omkareshwar temple bridge in Pune.
Four shots were fired at him from close range by the attackers believed to be in the age group of 25-30.
The assent to the anti black magic and superstition ordinance was given by Maharashtra Governor K Sankaranarayanan.
The angry protests sparked by Dabholkar's killing prompted the Maharashtra government to clear an ordinance to enforce the anti-superstition bill he had championed for years.
Dabholkar had drafted the Anti-Superstition and Black Magic Bill over a decade ago, but it repeatedly failed to get through the State Legislature.
The Bill had proposed that those indulging in black magic or preying on peoples' superstitions be jailed for up to seven years. It also sought to ban a range of practices including black magic, animal sacrifice and magical remedies to cure ailments.
The bill would be taken up for passage during the winter session of state legislature at Nagpur in December.
Accusing the Maharashtra government of being lax in arresting Dabholkar's assilants, Shiv Sena president Uddhav Thackeray said it was bent on "maligning" image of Hindu organisations by linking them to the killing.
"The perpetrators of Dabholkar's murder are still at large as police have failed to nab them even five days after the incident. We warn government to refrain from linking Hindu organisations to the murder and maligning their image," he told a party rally in Nashik.
Image: Followers of rationalist Dr Narendra Dabholkar remember him at a meet in Dadar, Mumbai
Photograph: Abhishek Mande-Bhot
It could have been my daughter!
Maharashtra governor signs anti-superstition bill
Shiv Sena MLA, who abused women staff at toll plaza, quits
Narendra Modi will drag Dawood back to India: Shiv Sena
'Fundamentalists will keep opposing anti-superstition bill'