The man shot dead by police after stabbing a young tourist in Brisbane's CBD this morning was on a counter terror watch list, police have revealed.

The 25-year-old was born in Afghanistan but had been living in Australia and was known to police, but detectives say at this stage they are not treating his actions as a terror attack.

The man, whose name has not yet been released, was shot by police after he stabbed an overseas tourist with a knife on Mary Street around 10am today.

The 26-year-old male victim was walking down Mary Street with a woman, at 10am when they were approached by the man, who they say was "behaving strangely".

He stopped in front of them and said nothing as he pulled a knife out of his bag, police say.

© 9News Forensic teams on Mary Street examine the scene of the crime. (9News)

© Nine Police have shot dead a man who charged at officers with a knife after stabbing another person in Brisbane's central business district.

The pair fled, with the woman making it back to their hotel room.

However, the attacker chased the man, and hit him in the face, breaking his nose and injuring his lip before stabbing him in the back.

Police say he was trying to run when he was stabbed.

"The male, the victim then turned to run away further. He then felt in his back something sharp, which we now believe he was stabbed," Detective Superintendent Tony Fleming told reporters.

Det Supt. Fleming says officers were alerted to the stabbing over their radio, prompting a police car to drive down Mary Street to confront the attacker.

They shot him after he approached them with a knife.

© 9News Detective Superintendent Tony Fleming said the man's motivations are currently unknown, but he was known to police. (9News)

"It will be alleged that the male person has confronted police, he has been armed with a knife and police have discharged their firearms," Det Supt Fleming said.

"They attempted to provide assistance to that man but he has subsequently died."

Police believe the attacker had two knifes on him during the incident, and that he acted alone.

Det Sup Int Fleming said the attacker was known to police and said a wide ranging investigation would take place, including looking at potential terrorism related motives.

Police are watching CCTV and examining the car the attacker travelled in to the city.

However, they said they don't believe there is any ongoing risk to the public.

"All the information to us at the moment was that this person was acting alone, came into the city alone, did those actions alone – but we just don't take anything for granted," Det Supt. Supt Fleming, said.

© Nine Invesigators examine evidence on Mary Street. (9News)

"We don't know the motivation for this attack today but obviously we treat it very seriously.

"Tragically a man has died, but it is my understanding that what police were confronted with today was a life-threatening situation and I'm very pleased that they are alive."

The victim was taken to Royal Brisbane Hospital, where he received stitches for his stab wound.

He has now been released and is being interviewed by police.

A guest of the Westin Hotel told AAP she heard several gunshots, but thought they were fireworks.

"I came outside and I saw someone lying on the ground and (police) were performing CPR," the guest told AAP.

Investigators from the Ethical Standards Command, the coroner and the Crime and Corruption Commission Queensland attended the scene as part of investigations into the incident.

Anyone with information about the incident is urged to contact Crime Stoppers on 1800 333 000 or at https://www.crimestoppersqld.com.au