The UN-backed Khmer Rouge tribunal in Cambodia is in the final stages of the trial of the two most senior leaders still alive.

Nuon Chea and Khieu Samphan are accused of crimes against humanity and genocide. They went on trial two years ago for allegedly orchestrating Cambodia's "killing fields" massacres more than three decades earlier.

The court is looking into the forced evacuation of the capital nearly 40 years ago, which was a part Khmer Rouge's plan to establish a classless communist state based on a rural agrarian economy. Khmer Rouge's four-year campaign of brutality ended up killing around two million people.

The court verdict is expected for early 2014.

Al Jazeera's Florence Looi reports from Phnom Penh.