It’s school lunch-break and Karim, 17, steps on to the pavement outside his Paris lycée gasping for a cigarette. He is studying sciences, wants to be an estate agent and finds school OK. But he always nips out at lunchtime for a puff. “It’s just the one cigarette. I’ve smoked since I was 16,” he says, taking a drag. “I like getting out of school to get some air. But, amazingly, these days the teachers would have allowed me to just light up a cigarette in the school courtyard.”

A floppy-fringed boy in an anorak agrees. His mum doesn’t know he smokes, so he didn’t want to give his name. But at 15 – still three years off France’s legal smoking age of 18 – he is delighted he is now able to have his 10am, midday and 3pm smokes in the school playground with school ashtray provided, rather than have to rush off the premises for a sneaky puff. “Staying in school to smoke saves so much time. You don’t have to run out of the school gate, then run back in to find your next lesson. It’s more practical and less stressful,” he says, exhaling.

Pupils suddenly being allowed to smoke inside high schools must be one of the weirdest side-effects of France’s current state of emergency. It has been four months since November’s terrorist attacks on Paris killed 130 people. But France is still living under a nationwide state of emergency made up of a raft of special powers that hark back to the Algerian war in the 1950s. The emergency measures – which have allowed police to conduct thousands of searches without a warrant or judicial oversight and place at least 290 people under house arrest outside the normal legal process – have sparked criticism from lawyers and United Nations experts. Rights groups have warned that Muslims have been unfairly targeted. There have been legal challenges.

But one of France’s lesser-known special safety precautions against terror attacks is that high-school children, aged around 15 and up, are now allowed to smoke in their own school playgrounds.

For decades, the huge crowds of Paris high-schoolers puffing away on pavements just outside their lycée front-doors in break-time, rolling tobacco – and a few of them, let’s face it, rolling other substances – has been firmly part of the Paris landscape. Hundreds of them do it. You can find your way to Paris’s lycées by following the haze of smoke during the 10am 10-minute break between philosophy and economics.

But these crowds of smoking teenagers started to make the state feel uneasy. If Paris was now vulnerable to cars full of gunmen with Kalashnikovs pulling up and firing on crowds, surely the school-age smokers were an easy target? It was a grim risk that schools no longer wanted to take. Particularly after a wave of hoax bomb threats against lycées last month. France remains haunted by a fear of children being targeted in terrorist attacks.

So, despite the legal smoking age being 18 and despite smoking being officially banned in schools and workplaces, a large number headteachers, encouraged by the ministry of education, have put in special measures under the state of emergency to allow kids to smoke inside their high-school grounds – in special outdoor areas of the courtyard or playground, with ashtrays provided. The health ministry is not happy about it, and some doctors have warned of the dangers, saying perhaps more are at risk from the effects of lifelong nicotine addiction than a potential attack. But in many schools, just keeping teenagers off the pavement is seen as a precaution worth taking.

“The times we live in mean that the feeling of danger on the street is very great. And when you put 1,000 pupils, or more, on a pavement in a city neighbourhood, the danger is immediate for us,” justifies Christel Boury, head of the Lycée Voltaire in the east of Paris.

“I was so shocked. I couldn’t believe it when they announced it,” says Léa, 17, who usually smokes at least one cigarette in her morning break, then during lunch, then at afternoon break, and then lights up as soon as she gets out of class. “Teachers have spent so long telling us smoking is bad for us and here they are giving us a special area of the school courtyard to do it in. Wow! It hasn’t made me smoke more, but for some people it probably has. Some who are really desperate manage to run down to the playground and have a super-fast smoke between classes, even if it’s not actually break-time.”

One of the biggest questions hanging over the wider state of emergency is when it will end. Once a government puts special measures in place, when can it safely say the perceived risk is over? The state of emergency has already been extended twice, and currently runs until 26 May. Public opinion largely approves. In February, when the state of emergency was extended for another three months, four out of five French people were in favour. Some people wonder whether it will be renewed again for the period of football’s European Championship in June.

In schools, headteachers are pondering whether to leave the new smoking allowances in place until the end of this school year. Outside his lycée, Vincent, 15, a non-smoker, shrugs: “Straight after the attacks, we were all pretty afraid. Now you just get on with life. If a terrorist really wanted to get into our school and attack us, they’d find a way to do it anyway.”