Climate strike: Children protest in Northern Ireland
Thousands of people have gathered in Belfast and Londonderry to protest against climate change.
Many schoolchildren were present as a demonstration began in Belfast's Cornmarket.
Some protesters held a short "die-in" to highlight the threat they say climate change poses to humanity.
The protests are among many taking place across the world, with pupils leaving schools and workers downing tools for a "climate strike" day.
A rally was held at Belfast City Hall at which there were calls for more action to combat global warming.
One of those taking part was Sarah Bell, whose tweet from the scene was retweeted by Swedish teenage climate activist Greta Thunberg.
"It was fantastic. It was amazing," Ms Bell said.
"I'm very much a big environmentalist - I would do a lot of beach cleaning and a lot of environmental work myself.
"Obviously she's very much an icon these days, so it was absolutely fantastic - I think my head exploded a wee bit. She's very inspirational being so young herself.
"It's so good to see that she's acknowledged the fact that we were striking today."
She said the protest itself had been very positive.
"It's just fantastic to see Belfast being shown in that way," she said.
"When I was there today it was very much positive and happy.
"There was lots of music and dancing and it was such a good atmosphere, nobody was angry or aggressive or anything, it was a very relaxed atmosphere."
Extinction Rebellion activist, Lorraine Montague from County Tyrone, was dressed as a swan to highlight the threat of climate change to wildlife.
She said: "Our climate is at crisis point and the government is not doing anything about it.
"We have to support the young people - they are the ones who started this strike."
'Nowhere to hide'
At Derry's Guildhall Square, hundreds of school pupils were joined by families and workers in the call for immediate action on climate change.
Emma Farren, one of the organisers of the Derry protest, said momentum was building locally and globally.
"Our last strike in July got about 15 people - now we are standing here and there are hundreds of people.
"There is nowhere to hide from it now," she said.
SDLP leader Colum Eastwood, Sinn Féin MP Elisha McCallion and Alliance Party leader Naomi Long were among the politicians taking part in the Derry protest.
Rallies are also taking place in UK cities including London, Manchester and Glasgow, urging "climate justice" and an "end to the age of fossil fuels".
Students and workers have also been encouraged to set off alarm clocks across the UK at 13:00 BST.
Energy Minister Kwasi Kwarteng said their voices were being heard.
However, he said he could not endorse children leaving school to take part.