Firefighters were called from across Lancashire and from Cumbria to help deal with the fire in the city centre.
It's believed to have started in a sauna at a health and fitness centre on Penny Street.
Around 40 firefighters were involved in the operation.
The fire service says the sauna and gym are on the third floor of a six-storey building, which was evacuated with no casualties reported.
Video by Adam Greenwood of events in Lancaster today:
Around 40 firefighters have been dealing with a fire in Lancaster city centre.
The operation's centred on a gym on Penny Street, after the alarm was rasied at around 10:15 today.
Part of the area's been cordoned off and several buildings are understood to have been evacuated.
This is the moment Lancastrian cricketer James Anderson received an OBE from the Prince of Wales for services to cricket.
The so-called "Burnley Express" became England's leading Test wicket-taker last year, surpassing Sir Ian Botham's milestone of 383.
Anderson has more than 430 test wickets and received the honour from Prince Charles during a Buckingham Palace investiture ceremony.
Engineers have been working around the clock to repair damage to overhead power lines and electricity substations caused by severe gales and flooding in Lancaster and Cumbria.
55,000 properties in Lancaster, Morecambe, Carnforth and the surrounding area could be without power for a number of days following flooding to a major electricity substation.
Engineers from the power company are working with Lancashire Fire and Rescue Service to determine when it is safe to access the flooded substation.
Lancaster University and its Students' Union have released a statement after two students were admitted to hospital suffering the effects of taking drugs.
A spokesperson said:
"We are committed to being proactive in providing students with information about the risks of taking drugs. Information is shared through all our channels and there is a zero-tolerance drugs policy at our venues.
Police alerted us to a drug circulating in Lancaster at the weekend causing people to be treated in hospital and we have issued a warning and advice to students.Fortunately it appears that none of the individuals involved were seriously affected.
Cat Smith, Labour MP for Lancaster and Fleetwood, writes about why she voted against her party on government reforms to welfare.Read the full story ›
A woman is still suffering 'episodes of agonising pain' more than two-and-a-half years after she drank a cocktail containing liquid nitrogen, her lawyer said.
Gaby Scanlon, from Heysham, Lancashire, was celebrating a 'low-key' 18th birthday with friends at Oscar's Wine Bar and Bistro in Lancaster in October 2012 when she drank the shot Nitro-Jagermeister.
Today, Oscar's Wine Bar pleaded guilty at Preston Crown Court to failing in the duty of an employer to ensure the safety of persons not in its employment and failing to ensure there was a safe system in place to prevent customers being exposed to injury from the consumption of the drink.
Welcoming the plea, the law firm representing Miss Scanlon and her family said the incident had "completely changed" the life of their client and that the effects had been "severe".
Patricia Noone, from Slater and Gordon, said:
"Gaby was an ordinary teenager with a bright future in front of her, but what happened on 4th October 2012, on what was intended as a low-key celebration for her 18th birthday, completely changed her life."
"She now suffers episodes of agonising pain and has been hospitalised several times. She has to avoid certain foods and can no longer enjoy eating, finding it hard to judge when she is full. She can only eat little and often and sometimes has to get up and snack several times during the night."
"She is unable to work full-time due to her lack of energy and frequent illness, and understandably her condition and the knowledge that crippling pain could attack her at any time has left her anxious."
"Gaby is a brave and determined young woman but there is no doubt that the effect on her has been severe. She has had to watch all her friends go off to university while she struggles to get her life back on track."
"Her hope and ours is that this serves as a warning to all bars and restaurants who must take responsibility for what they are serving to members of the public."
"It's reasonable to assume that what you are given in a bar or a restaurant is safe and they are legally obliged to make sure that is the case."
Oscar's Wine Bar Limited will be sentenced on September 17.
A wine bar has admitted health and safety failings which left an 18-year-old girl in hospital after she drank a cocktail containing liquid nitrogen.
Gaby Scanlon, from Heysham in Lancashire, was celebrating her birthday with friends at Oscar's Wine Bar and Bistro in Lancaster in October 2012 when she drank the shot Nitro-Jagermeister.
Miss Scanlon, now aged 20, said her stomach began to expand and she was taken to Lancaster Royal Infirmary where a CT scan found a large perforation.
The student spent three weeks in hospital as doctors removed her stomach and connected her oesophagus directly to her small bowel.
Today, Oscar's Wine Bar Limited pleaded guilty at Preston Crown Court to one count of failing in the duty of an employer to ensure the safety of persons not in its employment.
In its plea the company admitted it failed to ensure the shot cocktail was safe for customers to consume.
It also failed to ensure there was a safe system in place with adequate controls to prevent customers being exposed to injury from the consumption of such drinks, and it had not made any suitable and sufficient risk assessment.
A verdict of not guilty was recorded against bar employee Matthew Harding, of George Street, Lancaster, who denied failing in his duty to take reasonable care for the health and safety of others at work. His plea was accepted by the Crown. It had been alleged he presented the Nitro-Jagermeister at the customer's table when it was still producing cold nitrogen gases and was unsafe to drink.
Oscar's Wine Bar Limited will be sentenced on September 17.
The Queen has visited Lancaster to mark 750 years since the creation of the Duchy of Lancaster. But the show was stolen by one little boy and his teddies. Victoria Grimes reports.