Fantasy author George RR Martin was moved to reassure his fans on Wednesday that rumours buzzing around the web that he had died “have been greatly exaggerated”. His invocation of Mark Twain’s famous quote followed news that the Beatles producer George Martin had actually passed on that had panicked come hasty readers.

As tributes poured in for producer Martin, who died aged 90 on Tuesday evening, some readers mistakenly believed that Martin, author of the Game of Thrones novels, was no more.

But writing on his blog, the novelist told his fans that he was “not dead yet”. “While it is strangely moving to realise that so many people around the world care so deeply about my life and death, I have to go with Mark Twain and insist that the rumours of my death have been greatly exaggerated,” he wrote, referring to the novelist’s comment to a reporter in 1897 following rumours that he had died.

Martin the author said that the Beatles producer would be missed. “I never met Sir George (I did meet Paul McCartney once, for about a minute, while waiting for the valet to bring my rental car up at the Four Seasons in Beverly Hills), but like many millions of others, I loved the Beatles, and Martin’s contribution to their music is worthy of recognition and honour,” wrote Martin.

“As for me, I am still here, still writing, still editing, still going to movies and reading books, and I expect to hang around for quite a while yet, thank you very much. But thank you all for caring.”

Fans of the author are desperate for him to finish the sixth book in the A Song of Ice and Fire fantasy series, on which the HBO Game of Thrones television serial is based. The sixth season of the show is out in April, but Martin told fans earlier this year that The Winds of Winter, the sixth novel in the novel sequence, would not be released before the show aired.

“We all wanted book six … to come out before season six of the HBO show aired. Assuming the show would return in early April, that meant The Winds of Winter had to be published before the end of March, at the latest. For that to happen, my publishers told me, they would need the completed manuscript before the end of October. That seemed very do-able to me – in May. So there was the first deadline: Halloween,” wrote Martin in January.

“Unfortunately, the writing did not go as fast or as well as I would have liked. You can blame my travels or my blogposts or the distractions of other projects and the Cocteau and whatever, but maybe all that had an impact … you can blame my age, and maybe that had an impact too … but if truth be told, sometimes the writing goes well and sometimes it doesn’t, and that was true for me even when I was in my 20s.”

Refusing to set himself another deadline, Martin said the novel would “be done when it’s done. And it will be as good as I can possibly make it.”