Friends are searching for a mother and daughter who said "Please pray for me" as the fire blazed through Grenfell Tower.
Artist Khadija Saye, 24, who is currently showing her art work in the Venice Biennale, was in her flat on the 20th floor, with her mother, Mary Mendy, who is thought to be in her 50s.
Her friend, Nicola Green, said: "We're desperately trying to communicate with all the hospitals.
"We're told some people have been rescued up to the 19th and 20th floor. She was on the 20th floor. Nobody has any information at this point."
Ms Green told the Press Association that Ms Saye was last heard from at 3am when she was direct messaging from her flat, as her phone was not working.
"She was on Facebook saying she was unable to get out of the flat, that the smoke was so thick," Ms Green said.
"She was saying she just can't get out and 'Please pray for me. There's a fire in my council block. I can't leave the flat. Please pray for me and my mum.'
"At one point she said she'd just tried to leave again and said it was impossible. She said she felt like she was going to faint.
"Someone asked 'Did you try going down low with towels?' She said 'Yes, it's in my room'. I'm assuming she meant the smoke."
Ms Saye's work is currently on show in Venice, responding to the theme of diaspora.
Ms Green, who has mentored her friend and fellow artist for four years, added: "She's one of the most beautiful, kind and soulful people I've ever met. She always wears a map of Africa around her neck.
"We are all praying for her. She's got artists and friends and colleagues all praying for her."
She added: "She's got a huge career ahead of her. She's received an enormous amount of attention in her first major exhibition. She's an incredible, amazing, soulful artist."