Holly Marie Combs writes tribute to 'best friend' Shannen Doherty

Holly Marie Combs has posted an emotional tribute to her "better half," Shannen Doherty.

The actress, who was Shannen's co-star on hit TV show Charmed, posted the message on Instagram after Shannen died on Saturday, aged 53.

"My better half of 31 years. There is a hollow in my chest and I can't seem to catch my breath. A part of me is missing even though I know exactly what you would say to me right now," she wrote next to a carousel of photos of them together.

The 50-year-old added that Shannen loved her sons Finley, 20, and Riley, 17, as her own.

"They will walk with your sense of purpose and pride," she said. "They will be truthful and stand up for what is right. No matter what and zero f**ks given. Your fire will live on in them and the many other Charmed ones you helped raise."

She finished the tribute by writing, "A fierce fighter til the end. My most ardent champion. My loyal protector. My best friend. You taught me the meaning of family. You were and will be forevermore my sister. I love you."

Shannen and Holly starred together in Charmed between 1998 and 2000 when Shannen's character was killed off.

Shannen and Holly had previously claimed their co-star Alyssa Milano pressured the network to fire Shannen.

Shannen's publicist Leslie Sloane confirmed the Beverly Hills, 90210's star's death on Sunday in a statement, which read, "It is with a heavy heart that I confirm the passing of actress Shannen Doherty. On Saturday, July 13, she lost her battle with cancer after many years of fighting the disease."