From The Daily Mail so probably rumour
350 of them?
"Today an estimated 350 Britons clutching 'promissory notes' angrily crowded around check-in desks after they were refused permission to board flights. One British official described the scene as like 'the last days of Saigon'."
Seems Thai airways won't put them up in hotels.
http://www.dailymail.co.uk/news/worldnews/article-1268355/Iceland-volcano-Like-days-Saigon-stranded-British-tourists-cause-chaos-Bangkok-airport.html