Children are being left too tired to learn due to spending excessive hours online on their phones at home, teachers in Yorkshire have warned.

On Monday, the government issued new advice to schools intended to stop the use of mobile phones in classrooms.

But screen time at home should instead be a focus, some teachers have said.

Hannah Feerick, assistant head at Wales High School in Rotherham, said: "We're noticing students that tend to be quite quiet or sleepy in school time."

"They are spending a lot of time online," she added.

"We're also noticing a lot of issues in terms of conflicts between friendship groups when they're at a key time developing those friendship groups.

"A lot of that is happening online," Ms Feerick said.

According to data by No Phones At Home, which encourages people to disconnect from devices and focus on spending time together, 55% of children owned a phone by the age of 11, rising to 77% by the age of 12.

Of those children, 86% had social media accounts, with that group spending an average of 2.5 hours a day online using their phones, the Community Interest Company's figures showed.

At a recent meeting in Leeds, primary school teachers spoke of the impact spending too much time online was having on children.

One teacher told the BBC: "They're finding it hard to interact with others. They're quite solitary."

Another said: "There's a lack of patience and an ability to wait for a reward - they need to have it and have it now."

A third teacher said parents were "not seeing the complete impact" of the time children spent online.

Leeds-based psychologist Charlotte Armitage said parents needed to do their bit to make sure firm boundaries were in place on device use.

"It's about balance - everything in moderation," Ms Armitage said.

"We know mental health services, especially child and adolescent mental health services, are absolutely overwhelmed with children presenting with mental health problems.

"But we can stop that and all parents can do their bit to address their device use."

The government said its new guidance on mobile phone use in schools was part of a plan to "minimise disruption and improve behaviour in classrooms".

The advice came almost three years after the government first called for a ban on phones in schools.

But Pepe Di'lasio, head teacher of Wales High School, who is also the incoming general secretary of the Association of School and College Leaders, said the guidance was "shutting the door long after the horse has bolted".

"The government should do far more [to chase] those online platforms that children can access and share quite disturbing and extreme content," Mr Di'lasio said.

"This is the area we need to focus on - not the hard device, not the issue of having the device during the school day."