Three people are believed to have been stabbed to death in a hotel stairwell in Glasgow city centre.
Armed police shot the suspect, who is also understood to have died.
The Scottish Police Federation have confirmed a police officer was stabbed. Armed police remain at the scene outside the Park Inn in West George Street.
A statement from Police Scotland said the situation was "contained" and there was no danger to the general public.
First Minister Nicola Sturgeon said reports of the incident were "truly dreadful" and she was being "updated as the situation becomes clearer".
She added: "My thoughts are with everyone involved."
Prime Minister Boris Johnson said he was "deeply saddened by the terrible incident in Glasgow".
Police Scotland Assistant Chief Constable Steve Johnson urged people to avoid the area.
Multiple armed officers can be seen entering a building beside the Park Inn hotel on West George Street in #Glasgow.
— Greatest Hits Radio News (@ghrnewsuk) June 26, 2020
Police are asking the public to avoid the area. pic.twitter.com/9OGnHTUMa9
