At least 20 survivors and witnesses of the deadly Grenfell Tower fire accident have attempted suicide since the incident, a charity has claimed and warned that many more such cases could arise in the coming days.

The blaze that broke out on 14 June charred the 24-storey residential block in North Kensington, London, destroying nearly 150 houses. Around 80 people died, with some 70 people reported injured in the fire that continued to rage for more than two days.

Silence of Suicide founder Yvette Greenway told the BBC that many residents were unable to get images of the fire accident "out of their minds".

"There is a lot of alcohol and drug dependency. People are feeling isolated," she added.

Greenway said that the data on suicide attempts was based on conversations between the affected residents of Grenfell Tower and volunteers helping them cope with the trauma. Judy Bolton of Justice4Grenfell charity also confirmed that their volunteers working with the survivors had told her of 20 suicide attempts. However, the numbers could not be independently verified.

Speaking about the "council-led" mental health services being provided to the survivors, both Greenway and Bolton said they were inadequate and required rethinking.

"We've been told workers are going around putting leaflets under hotel doors and not actually speaking to people," Greenway said. She warned that "many more instances of PTSD [post-traumatic stress disorder], depression, anxiety and self-harming" would arise in the coming days "as people reach different stages of trauma".

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Charity groups claimed that at least 20 Grenfell Tower fire survivors have attempted suicide since the June accident that killed nearly 80 people - File photo Toby Melville/Reuters

"Everybody will be affected at different times. We need long-term mental health provision for the next three decades at least — maybe longer," Greenway noted.

Bolton said that the survivors urgently needed trauma and bereavement counselling. "There just isn't the proper psychiatric help that people need," she said and added that the affected people were "self-medicating" themselves to forget the trauma.

"We were flooded with drug dealers praying [sic] on the traumatised. People saw their neighbours falling from a burning building.

"They saw children being dropped from the building. There are ashes still blowing over us when the train goes past. We're being covered in the ash of our dead friends and relatives," Bolton, a nurse for 20 years, told the broadcaster.

The fire incident was blamed on inadequate safety measures in the residential tower. An inquiry was underway to find out the actual cause of the fire.