A ban on mobile phones in Jersey schools has come in to force for the new academic year.
The Education Minister wrote to parents in June, saying phone use would be not be allowed in government schools and colleges from September.
Previously headteachers could decide their school's phone policy.
Deputy Rob Ward said restrictions for all pupils up to the end of Year 11 would provide consistency, reduce distractions and promote online safety.
He advised against sending children into school with a smartphone at all, and said students who attempt to evade the rules will face consequences.
"Where a student actively evades policy to use a phone (they) will be dealt with according to school behaviour policy.
“If access is discovered of inappropriate sites and content, we will not hesitate to involve the police, should it be of a severe nature."
It comes amid growing concern about the impacts of excessive screen time on young people - including anxiety, lack of sleep and online harms.
The mother of murdered teenager Brianna Ghey is calling on the UK Government to ban mobile phones in all schools.
Esther Ghey says a ban would safeguard pupils and improve behaviour and engagement.
She says Brianna struggled with phone addiction before she was killed in 2023.
"She wanted to be on social media - she just wanted to live online.
" All the arguments that me and Brianna had were down to her phone use, but even in school she had issues and I used to have phone calls from the school saying Brianna wouldn't put her phone away."
Brianna's former school, Birchwood Community High in Warrington, brought in a ban after her death.
Headteacher Emma Mills says it's had a huge impact:
"About 90% of our safeguarding incidents previously were related to phones and social media. Since the phone ban, it's just 10%.

Ombudsman issues advice about mis-sold car loans
'Music Muratti' for young musicians in the Channel Islands
Jersey celebrates 81 years of Liberation
Victoria College twins with secondary school in Bad Wurzach
Jet2 increases capacity to Jersey by 140% for summer 2027
10-day Liberation International Music Festival gets underway
Flower mural in St Brelade's dubbed 'graffiti' and covered up
Future politicians called to action over visitor economy at 'tipping point'