Schools have reopened, with around 2 million pupils heading back to classrooms after a three-month summer break. Nearly three years after Taliban gunmen shot Pakistani schoolgirl Malala Yousafzai, the teenage activist last week urged world leaders gathered in New York to help millions more children go to school. World Teachers' Day falls on October 5th, a Unesco initiative highlighting the work of educators struggling to teach children amid intimidation in Pakistan, conflict in Syria or poverty in Vietnam. The following photographs show the remarkable differences and similarities between classrooms around the world.

First grade students and their class teacher Teruko Takakusaki (in background) pose for a photo during their homeroom period at the end of the school day at Takinogawa Elementary School in Tokyo, Japan. (Toru Hanai/Reuters)

Year 10 high school students from a vocational program with a maritime focus pose for a photograph at Artes y Oficios Melchor Lasso de la Vega school in Panama City. (Carlos Jasso/Reuters)

Children of the Satere Mawe Indian tribe school at the Sahu Ape village pose for a picture in Manacapuru, Amazonas state, Brazil. (Bruno Kelly/Reuters)

Teacher Mahajera Armani and her class of girls pose for a picture at their study open area, founded by Bangladesh Rural Advancement Committee (BRAC), outside Jalalabad city, Afghanistan. (Parwiz/Reuters)

Third grade students attend class at the Mashal Model School on the outskirts of Islamabad, Pakistan . The Mashal Model School founded by Zeba Husain caters to children of underprivileged families from different parts of Pakistan and Afghanistan. (Caren Firouz/Reuters)

Students cross their arms to demonstrate they are listening carefully to their teacher at Al Hakim El Kassar Primary School in Tunis, Tunisia. (Anis Mili/Reuters)

Giang Thi May teaches a first grade class at the primary school of Van Chai in Dong Van district, on the border with China, north of Hanoi, Vietnam. (Kham/Reuters)

Students in Dr. Hugh McCormick's lower sixth politics division (year 12) sit in their classroom in Old Schools on the last day of term at Harrow School in Middlesex, Britain. (Suzanne Plunkett/Reuters)

Tahfiz or Koranic students pose for a photograph in Madrasah Nurul Iman boarding school outside Malaysia's capital city, Kuala Lumpur. There are 36 male students at the madrasah, ranging from 11 to 18 years of age. (Olivia Harris/Reuters)

Students in Irena Chmura's Salusbury World class, which includes students from Year 1 to Year 6, pose in their classroom in London, Britain. (Suzanne Plunkett/Reuters)