Every three minutes, the sound of a metro train passing overhead reverberates through the school under the bridge. SHOWKAT SHAFI/AL JAZEERA
New Delhi, India - Each morning, before he opens his grocery store, 46-year-old Rajesh Kumar Sharma heads to a metro bridge in the east of India's capital, New Delhi.
It isn't the bridge that interests him, but what goes on beneath it.
For this is where he founded what he affectionately calls the free school under the bridge.
With no walls, the pillars of the bridge serve as a boundary. But for the roughly 300 pupils - mostly children of impoverished migrant labourers, daily wage workers and seasonal farmers - it offers the chance of an education.
"I started this school in 2006 and this year we are celebrating 10 years of the school," Rajesh explains.
"I didn't want this generation to lose out just because they are poor."
It is a deeply personal issue for the shopkeeper.
"I could not become an engineer because of financial constraints. I had to drop out of college. Through these children I get to live my dream," he says.
The school runs two sessions a day - two hours for boys in the morning and two hours for the 120 girls who attend in the afternoon.
Most of the pupils are enrolled in nearby government-run schools, but the free school under the bridge offers them the additional tuition in mathematics, English, Hindi, science, history and geography they need to get by.
"We encourage students to join the government school because they get many benefits from it, such as free meals," Rajesh explains.
"This school gives them additional help to understand the syllabus. In government schools, boys have to attend the afternoon batch, so they attend our free school in the morning and after that go to their government schools while girls attend government schools in the morning and they come to our school in the afternoon."
The students have left their mark on their school - painting brightly-coloured murals on the platforms of the bridge.
They sit on donated mats, while the teachers use donated plastic chairs. Two steel trunks store the attendance registers and other paperwork.
Every morning, before class begins, the students sweep the floors.
Laxmi Chandra teaches mathematics and science at the school.
The son of a daily wage labourer from the Indian state of Bihar, he believes poverty can drive children to crime.
"I have been teaching here since 2011 and back home I have seen how, due to poverty, children got into all sorts of wrong things," he says.
"They need guidance and that's what we try to give them here through education, so that they can have a bright future."
Fifty-five-year-old Ramesh Chander rides three kilometres on his bicycle each day to take his granddaughter, Lalita Kumari, to the school under the bridge. SHOWKAT SHAFI/AL JAZEERA
Pupils help to clean up before class begins. SHOWKAT SHAFI/AL JAZEERA
Each Saturday, the pupils do physical exercises. SHOWKAT SHAFI/AL JAZEERA
According to UNESCO, 17.7 million children and adolescents do not attend school in India. SHOWKAT SHAFI/AL JAZEERA
The pupils at the free school under the bridge are mostly the children of migrant workers, labourers, rickshaw-pullers and seasonal farmers who live in the nearby slums. SHOWKAT SHAFI/AL JAZEERA
Kanchan Yadav is a voluntary teacher at the school. 'My children go to private school and I want these poor children to also grow and make a good career,' she says. SHOWKAT SHAFI/ AL JAZEERA
Official figures indicate that more than 12 million children are made to work in India, but many NGOs say the real figure could be as high as 60 million. SHOWKAT SHAFI/AL JAZEERA
'I am a college dropout because of financial difficulties, but I want to make sure that the poor kids achieve what I couldn't,' says the school's founder, Rajesh Kumar Sharma. SHOWKAT SHAFI/ AL JAZEERA
School hours are from 9am to 11am for boys and from 2pm to 4pm for girls. SHOWKAT SHAFI/AL JAZEERA
Pupils from nursery to class 8 attend the free school. SHOWKAT SHAFI/AL JAZEERA
'This free school helps us to learn more than what we can in our school. Teachers in government school don't give us much attention, but here they ensure that we are taught properly,' says Reshma, a student at the school. SHOWKAT SHAFI/AL JAZEERA
'We can't afford private tuition as I have five daughters and two sons. The only way I can help them is by sending them to the free school. It's a god's gift to the poor like us, as even our children get the opportunity to study,' says Kalasho Devi, who lives in a nearby slum. SHOWKAT SHAFI/AL JAZEERA
Each pupil who attends the school is formally registered with their name and photograph. SHOWKAT SHAFI/AL JAZEERA
Volunteers from the surrounding area teach at the school. SHOWKAT SHAFI/AL JAZEERA