The offence was registered hours after the opposition party threatened to begin a protest.
Police on Thursday registered a First Information Report (FIR) against BJP workers over a clash outside the Congress' office in the Paldi area here.
The offence was registered hours after the opposition party threatened to launch a stir if no action was taken over Tuesday's incidents.
The BJP had protested outside the Congress office on Tuesday over the alleged anti-Hindu remarks of Lok Sabha Leader of Opposition Rahul Gandhi.
"We have taken a complaint from Congress and registered an FIR. No one has been arrested yet," said Inspector B D Jhilaria of Ellisbridge police station.
Earlier in the day, Gujarat Congress president Shaktisinh Gohil threatened to launch a protest claiming that police were not registering an FIR against BJP workers even after various pieces of evidence established that they were involved in the attack.
Rahul Gandhi may visit Ahmedabad on July 6 and meet the Congress workers who stood their ground when stones were hurled at them, he said.
The state unit of the party has already extended an invitation to Gandhi and was confident that he will accept, Mr Gohil added.
A clash broke out between BJP and Congress workers outside Rajiv Gandhi Bhavan, Congress's state headquarters, on Tuesday after BJP youth wing members reached there to protest against Rahul Gandhi's remarks in his maiden speech as Leader of Opposition.
According to police, both sides engaged in stone pelting in which five policemen including an Assistant Commissioner of Police were injured.
On Wednesday, Ellisbridge police registered two FIRs, and arrested five Congress workers under relevant sections of the Bharatiya Nyaya Sanhita (BNS) for offences including unlawful assembly, rioting, endangering life or personal safety of others and causing hurt to an on-duty public servant.
While the first FIR was registered against nearly 450 workers of both Congress and BJP on the basis of a complaint given by injured police constable Karmraj Bhagvatsinh, the other was based on a complaint filed by the youth wing of the BJP's Ahmedabad unit.
On Thursday, hours after Gohil threatened to launch a stir, police registered another FIR against 15 BJP workers and a mob of 100 to 150 persons.
It was based on a complaint filed by working president of the Gujarat Congress, Himmatsinh Patel.
BJP's youth wing workers threw stones at Congress workers, injuring a few, the complaint alleged.
The FIR registered on the basis of the complaint given by constable Karmraj Bhagvatsinh named local Congress leader and Leader of Opposition in the Ahmedabad Municipal Corporation Shehzad Khan Pathan and fellow party workers Pragati Ahir and Hetaben Parikh as accused besides a mob of some 250 Congress workers and 200 BJP workers.
It was Congress workers who first charged at BJP activists after being incited by some Congress leaders, and when police tried to stop them, the mob started throwing stones and thick wooden sticks towards BJP activists, it claimed.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)