Former US President Jimmy Carter got in a shouting match with Sudanese security officials Wednesday, accusing them of preventing him from meeting with representatives of ethnic African refugees in Darfur. The 83-year-old Carter yelled at the head of the local security services as he tried to walk into this pro-Sudanese government town to meet with refugees, who were too frightened to attend a previously scheduled meeting. "No you can't go. It's not on the program," the local chief of national security, who only gave his first name as Omar, yelled at Carter. "We're going to anyway," an angry Carter retorted to the security, telling them they didn't have the authority to stop him. There was no physical altercation.