The world is facing a huge human tragedy in Darfur unless the international community intervenes, according to the humanitarian organisation Concern.
Speaking after a visit to the region, Concern Worldwide chief executive Tom Arnold called for political action to enforce a ceasefire in the war-torn region.
The UN has warned that if the security situation doesn't improve, it may pull out its humanitarian aid teams.
Concern claims that 12 aid workers have been killed in Darfur since last July and a further five are missing.
Mr Arnold said: "Unless there is increased recognition, within Sudan and internationally, of the scale of the humanitarian crisis in Darfur, we will be faced with a huge long-term human tragedy.
"The only way to prevent this is for urgent political action to improve security in the short-term and to start a meaningful longer term peace process."
He added: " I have met people in West Darfur who were forced to flee their villages by militia who had also stolen their animals and crops.
Mr Arnold was pessimistic about quick solutions, saying Concern was working on the assumption that its camps for the displaced would still be there in 2012.
"The crisis will only worsen through 2007, for displaced people and aid workers, unless there is greater recognition from the international community, and a significant improvement in security," he said.
"At least another five years is the working assumption for our camps, by which time they will house eight-year-old children who were born there. If things continue the way they are, these people may never get out of these camps," Mr Arnold said.
"People are afraid to go outside the camps for fear of being attacked. One local leader said they were living in an open prison. I met nobody who said they were willing to return to their villages without a major improvement in security," he said.
Mr Arnold visited refugee camps run by local programmes assisted by Concern.
Agencies