Nearly two months after the signing of a peace accord between Sudan and a rebel group in Darfur, the humanitarian situation there appears to have worsened, while Khartoum-backed Janjaweed militia continue to attack towns and villages in neighbouring Chad. Human rights groups and others are calling for urgent action by the African Union (AU) and the United Nations to prevent the violence from further destabilising the entire sub-region along Sudan's lengthy western border.