Meanwhile, Vin Diesel posted on Instagram: "Brother I will miss you very much. I am absolutely speechless. Heaven has gained a new Angel. Rest in Peace."
The pair were joined by a number of stars and fans paying tribute to Paul, who is survived by his 15-year-old daughter.
Zoe Saldana - who appeared with him in 2010 movie
Takers
- said: "A very sad day indeed. R.I.P. Paul Walker. Our prayers are with you and your family."
Liam Neeson also joined in the outpouring for the late star, writing that his "heart goes out to his friends and family".
He tweeted: "Just heard about Paul Walker... Very sad tragic car accident. My heart goes out to his friends and family. Love. #RIPPaulWalker"
Australian director James Wan said he was "beyond heartbroken" by Walker's death.
Wan and Walker had been filming Fast and Furious 7, the latest chapter of the blockbuster action movie franchise co-starring Vin Diesel and Dwayne Johnson.
Walker, in recent interviews, had been full of praise for the fresh look the Melbourne director of horror films Saw and The Conjuring had given the seventh chapter.
"I am so beyond heartbroken right now," Wan wrote on Twitter. "I can't process anything."
How I Met Your Mother actor Neil Patrick Harris also took to Twitter, contemplating about "how things can just end so suddenly".
He said: "Such sad news about Paul Walker! It's so tragic and crazy how things can just end so suddenly. My condolences to his family."
All my strength, love & faith to the Walker family during this heartbreaking time. We find our strength.. in his light. Love you brother.
.@RealPaulWalker May he be in peace. To his family you are in our thoughts and prayers.
RIP Paul Walker http://t.co/KdPeH0eZQx
Paul Walker was probably the most beautiful American movie actor of the past two decades.
I am so beyond heartbroken right now. I can't process anything.
- Bang! Showbiz