They have also been used as goodwill gestures, sometimes seen as efforts to influence popular opinion - for example by boosting the popularity of Palestinian Prime Minister Mahmoud Abbas.

BBC: Who are the Mid-East prisoners?

They point in mitigation to such goodwill gestures as granting free admission to state universities for students from Darfur, and note that it was the rebel parties, not the government, which failed to show up for recent peace talks.

ECONOMIST: Peace in the south, war in the west and poverty amid riches