Rubbish is piling up in Bamako, the capital of Mali – especially along the banks of the Niger River. The riverside is covered with decomposing organic material, plastic and scraps of metal. Our Observer filmed these unauthorised dumps to denounce inaction on the part of the authorities.

There are more than two million people living in the Malian capital and, like many large African cities, it has struggled to manage its waste. There are at least 40 unauthorised dumps where rubbish is piling up and polluting the air, water and soil. In 2008, Forbes ranked Bamako as the 16th dirtiest city in the world.

Omar Sissoko, age 21, is a student in history and archaeology in Bamako. Inspired by an initiative launched by our Observer Fatoumata Chérif in Guinea, he started making videos of unauthorised dumps in Bamako and sent them to our team.