The United Nations High Commissioner for Refugees Antonio Gutteres warns the worsening situation in Sudan's Darfur region threatens to spark another round of mass displacement that could destabilize the entire region. He is calling for rapid international action to improve security.

High Commissioner Antonio Gutteres says deteriorating security is making it very difficult for humanitarian agencies to provide even minimum help to some two million people made homeless by the war in Darfur. His spokesman, Ron Redmond, says this bad situation is worsening by the day.

"Mr. Guterres notes that millions of people are already at grave risk and urgent international attention is needed to put pressure on the parties to the conflict and to convince everyone involved on the ground to let humanitarian agencies safely carry out their work," he said. "Lives depend on this, he says, and if things do not improve, we are heading for a major catastrophe."

Sudanese government-backed Arab Janjaweed militia have been fighting with black African rebel groups for the past three and one half years. Tens of thousands of people have been killed, more than two million people have become internally displaced and at least 200,000 refugees have fled to neighboring Chad.

Since May, a dozen aid workers have been killed and humanitarian convoys are repeatedly attacked and vehicles stolen. The U.N. refugee agency has six offices and nearly 100 staff in South and West Darfur to carry out its protection monitoring activities. But, Redmond says the situation has become so dangerous, monitors have to use helicopters to get around to see what is happening to the internally displaced people.

"That is becoming ever more difficult to achieve," he said. "There are still disturbing reports of abuses, of rapes, sexual and gender-based violence, killing people who are unable to leave IDP [Internally Displaced People] camps. So it is a very, very serious situation and the High Commissioner is extremely concerned about it, particularly from the perspective of how we would deal with another massive displacement, were it to occur."

Guterres warns the crisis could increase instability in bordering areas of Chad and the Central African Republic. He notes Chad is hosting more than 200,000 refugees from Darfur and another 46,000 from the Central African Republic. He says the country is close to breaking point.

The Khartoum government opposes the deployment of 20,000 U.N. troops and police to the Darfur region. In addition, thousands of Sudanese troops have been sent to Darfur in recent weeks. The U.N. refugee agency says this is prompting fears of a major military offensive that could lead to more displacement.