Portraits of schoolchildren by the artist Steve McQueen have been unveiled on billboards across south east London.

The Oscar-winning filmmaker, 50, photographed thousands of London’s Year Three pupils, in traditional-style class snaps with rows of smiling children alongside their teachers, for a “visual portrait of citizenship”.

The portraits will go on display on 613 locations on roadsides, railways and underground stations, including in Bromley, Lewisham, Greenwich and Dartford.

They capture pupils aged seven and eight, a “milestone” age at which they “become more conscious of a much bigger world beyond their immediate family”.

The 12 Years A Slave filmmaker said: “The seeds of this project started 21 years ago with the birth of my first child, a milestone that put my own journey in perspective.

“My hope is that through the billboards millions of Londoners can reflect on the past, the present and the future not only of themselves but of their city.

“I am very excited that this portrait of London will be seen by so many people as part of their daily life in this great city that I love.”

Turner Prize-winner McQueen invited all of London’s Year Three school pupils to take part but ended up with 76,000 children – around two thirds of London’s seven to eight-year-olds.

The outdoor work is a collaboration with Artangel, known for producing unusual art in unexpected places.

James Lingwood, co-director of Artangel, said: “Year 3 is a resounding expression of Artangel’s belief that art can be anywhere. It’s a celebration of children and a question to the rest of us – what kind of future are we making for them?”

The outdoor project will be followed by a “vast” free exhibition at Tate Britain featuring thousands of class photographs of Year Three pupils.

Tate director Maria Balshaw has previously said it “may well be the most ambitious art work we have ever shown at Tate Britain”.

The outdoor exhibition on billboards across London runs until November 18. The Tate Britain exhibition opens on November 12.