Shireen was taken into custody on Monday, her fourth arrest in 10 days, from outside Adiala Jail after she was released on court orders in another case.
In her brief presser, the former federal minister cited her health issues and the trouble that her daughter Imaan Zainab Mazari had to go through during her multiple "abductions and release", as the reasons for her decision.
She categorically told media persons that said that she wouldn't be a part of PTI or any other party, from now onwards.
Shireen also said her husband had passed away five months ago, and added, "My children, mother and health are now my priority."
Speaking about the violent protests following the arrest of PTI chief Imran Khan, she said, "I condemn the violence on May 9 and 10. I also gave an undertaking to the Islamabad High Court in this regard."
She added, "Not just May 9 and 10; I have always condemned the violence on state symbols like GHQ, Parliament and Supreme Court."
Riots broke out earlier this month as the supporters of PTI chairman Imran Khan went on a rampage against his arrest from the IHC premises in the Al-Qadir Trust case. As the unrest ensued, the protesters torched government and military installations, and attacked an army vehicle in at least one recorded case.
Some reports in the media suggest that more first-tier PTI leaders are expected to announce the decision to leave the party. Most of the party activists who announced to leave the Imran-led outfit, cited May 9 attacks as the reason.
According to them, they have no association with the mobs who launched attacks on the government and army installations, and that they will no more be a part of the former ruling party.