Kim Cattrall Tells SJP ‘You Are Not My Friend’ 4 Days After Thanking Costars Following Brother’s Death

On Saturday, Kim Cattrall — who is grieving the recent death of her brother, Chris — sent a message to her former Sex and the City costar Sarah Jessica Parker, telling her “You are not my friend” and “I don’t need your love and support at this tragic time.”

Cattrall confirmed on Sunday that her 55-year-old brother Chris had been found dead — just hours after asking fans to help find him after he went missing in Canada.

After learning of the tragedy, Parker had reached out to her privately and had written a supportive comment on social media: “Dearest Kim, my love and condolences to you and yours and Godspeed to your beloved brother. Xx.”

It initially appeared Cattrall was receptive to Parker’s messages of condolences, thanking her and other SATC colleagues for “the outpouring of support for myself and my family” on Twitter Tuesday.

Cattrall began criticizing her former SATC costars last year after Parker revealed that plans for a third SATC movie had been scrapped. Sources said that Cattrall’s demands had derailed the project; Cattrall denied this, saying she never agreed to do the film. In October she told Piers Morgan that she’s “never been friends” with her SATC costars.

Parker has not responded to Cattrall’s Saturday Instagram post, but she did address Cattrall’s previous remarks to PEOPLE last week during an interview for an upcoming story about her HBO show Divorce, her new Gap Kids line and other projects.

“I never responded to the conversation that Kim had with Piers Morgan, where she said things that were really hurtful about me,” Parker tells PEOPLE. “I don’t want to answer it, that’s not how I feel about her. I think of her as part of this [Sex and the City] experience and it was amazing. We had a connection with the audience, and we had a connection with this city and with this crew and we got to tell these crazy stories with each other. And I don’t want to mess with that.”

Parker says that after Cattrall’s brother went missing earlier this month, “I rang and I didn’t get her and I texted her. And then when I learned he passed I reached out. I can’t imagine what it’s like for her right now.”