MUMBAI: Shiv Sena (UBT) chief Uddhav Thackeray and Maharashtra Deputy Chief Minister Devendra Fadnavis on Saturday exchanged barbs over each other's mental condition against the backdrop of the February 8 firing incident in suburban Dahisar in Mumbai.

Responding to the killing of Shiv Sena (UBT) leader Abhishek Ghosalkar during a Facebook Live session by social activist Mauris Noronho, who also ended his life, Fadnavis had on Friday brushed aside demands for his resignation.

"This (Ghosalkar's killing) is a serious incident, but even if a dog were to come under a vehicle, they (opposition) will seek the home minister's resignation," Fadnavis, who holds the Home portfolio in the Eknath Shinde government, had said.

Addressing a press conference in Mumbai on Saturday, Thackeray slammed the remarks and wondered if the state had a "mentally ill" home minister.

"I had earlier called him (Fadnavis) a blot, useless. But, now I don't have words. Cruel. I feel he should be checked mentally. His comment (on the killing of Ghosalkar) sounded like our state has got a mentally-ill home minister," Thackeray said.

Hitting back, Fadnavis said, "Uddhav Thackeray has lost his mind. I can only say get well soon."

The deputy CM was speaking to reporters in Nashik.

Once known to share warm relations, ties between Thackeray and Fadnavis turned acrimonious after the (undivided) Shiv Sena broke its longtime alliance with the BJP post the 2019 Assembly polls over sharing the chief minister's post.