Children are putting their health at risk by blowing their pocket money on hookah pipes at illegal shisha dens, police have warned.
In one alarming incident, officers revealed that a girl had celebrated her 12th birthday with a three-hour party in a cafe.
She had spent £30 she had been given as a present on the flavoured water pipes along with a number of friends.
Shisha cafes, in which customers smoke through a pipe can be licensed but they must adhere to strict health and safety guidelines
Legal: But shisha cafes haves to meet strict regulations and must not serve tobacco to children .
Operators should also abide by smoking legislation, including only selling products to adults and not allowing smoking 'inside'.
Trading standards departments across the country have noticed a proliferaiton in shihsa cafes which are becoming increasingly popular with school age children.
Chris Allen, the head of public protection for Blackburn, said his officers were now overseeing multiple investigations into shisha dens.
He said that from 'menus' his officers have seen at one premises, smokers were charged between £5-£6 per session.
Mr Allen described the dens as Bedouin-style premises decked out with floor cushions, drapes, and said 'dodgy wiring' and hot coals were fire hazards.
He said: 'What we usually find is upwards of 20 or 30 people in these upstairs rooms and we've seen places where there are 30 to 40 shisha pipes available
'This is an emerging issue countrywide and if any local authority is doing its homework they'll find a problem.'
Mr Allen said he believed the illegal dens had arisen out of a competiton from the number of cafes in the areas and people looking for alternative methods of income.
He added: 'The reason why this is proliferating is the profitability which comes from selling shisha and the access to the pipes
'This is one which seems to have caught the imagination.
'My message to children would be that the health implications of shisha smoking will be felt by all who take part in it, but the younger someone starts to smoke, the greater the risk of them suffering ill-health in adulthood'
Town centre licensing officer Andy Duxbury said: 'We are not trying to ruin anyone's legitimate business or stop their culture.
'But we have a real concern about schoolchildren spending Friday and Saturday nights in these places.
They are paying money to smoke the flavoured tobacco and their parents don't know where they are.
'We have a lot of intelligence that it is children from 12 to 16, from all races, using them as social meeting places in the town centre.
'Our main concerns are the premises themselves and the health risks to the children'