It is understood the extra measures include an increased police presence at the Queensland Parliament and in the Brisbane CBD, and police officers being told to get out on the beat.

Premier Annastacia Palaszczuk said Queenslanders had woken to tragic news from London.

"An incident of barbaric violence outside the Houses of Parliament has left five people dead and around 40 people injured," Ms Palaszczuk told Queensland Parliament on Thursday morning.

"The dead include a police officer and the apparent assailant.

"This incident is even more disturbing because the name Westminster sits at the very heart of our democratic institutions."

Police Commissioner Ian Stewart briefed Ms Palaszczuk and Police Minister Mark Stewart on the Queensland security situation on Thursday.

"While there is no suggestion of a need to elevate our threat level, he believes it prudent to increase the security presence around certain parts of Queensland while assessments continue on the situation in London," Ms Palaszczuk said.

Commissioner Stewart will also brief Speaker Peter Wellington and the clerk in relation to security measures at the Queensland Parliament.

Ms Palaszczuk said the thoughts and prayers of Queenslanders were with the victims.

"The people of Queensland stand in solidarity and sympathy with our friends and colleagues in London after this appalling and shocking event," she said.

Brisbane's Deputy Mayor Adrian Schrinner said Brisbane stood in solidarity with Britain and would show support by lighting city icons.

"The Story Bridge and City Hall will be lit in red, white and blue tonight to show our support for the people of Britain," he said.

"Our city's collective thoughts and prayers are with the victims and their families."

Mr Wellington said he was writing to his counterparts in London to send condolences, and would take advice to ensure the safety of the Queensland Parliament.

Extra police are guarding Parliament House in Canberra on Thursday in the wake of the deadly attack in London.

Commissioner Stewart promised a greater police presence on the streets but said there was no reason for people to feel nervous.

"It is important that they understand that there is no credible threat (to Queensland) or linkage to the London issue, and we want Queenslanders to go about their daily business," he told reporters.

"But we'd ask them also to be alert, to please let us know of any suspicious activity that they might see."

"If you're worried about it, ring us and let us take care of it."

In a statement, the QPS said there was no known specific threat to Queensland.

Opposition Leader Tim Nicholls described the London attacks as shocking and tragic.

"[We're] sending our thoughts and prayed to the families of those innocent victims in this, yet another act of senseless terrorism," Mr Nicholls said.

Sign up for Spencer Howson's daily news email for everything a Queenslander needs to start their day

- with AAP