Six people are being treated in hospital for their injuries, including a 42-year-old police officer who was said to be "critical but stable".
Sources had earlier suggested two other people had died at the Park Inn in West George Street, which is currently being used to house asylum seekers.
Police said the incident was not being treated as terrorism.
The other injured men in hospital are aged 17, 18, 20, 38 and 53.
A police spokesman said the situation was "contained" and there was no danger to the general public.