DR Congo: Why are UN blue helmets there?

Elections are due to take place in the Democratic Republic of Congo on Sunday.

After 17 years in power, President Joseph Kabila is standing down and campaigning has been marred by widespread violence.

There have also been concerns over the conduct of the poll, which has been delayed because of logistical problems.

The country has been wracked by conflict over many years, and one constant feature has been the presence of United Nations peacekeepers.

It's one of the largest, and most expensive UN operations in the world. So, why are they there and when will they leave?

Video produced and primary research by Nadeem Shad

Motion graphics by Jacqueline Galvin

Additional research by Christopher Giles