The US has reiterated a warning after Saturday's attack on foreigners in Saudi Arabia for American citizens in the kingdom to leave. The State Dept. referred US citizens to a message issued on 15 April saying: "Private American citizens currently in Saudi Arabia are strongly urged to depart." The move came as the Western petrochemical firm ABB targeted by insurgents in the attack said it was evacuating some staff after five of their colleagues were killed. There was no immediate indication if the latest attack would prompt an exodus among the 35,000 resident Americans - a move that could badly damage the economy of the world's biggest oil exporter. Two Americans, two Britons and an Australian were killed in the shooting. The body of one victim was dragged by car through the streets of the Red Sea industrial city. A Canadian citizen was shot in the neck and remains in serious condition. **Staff evacuated*** ABB said on Sunday it would be evacuating all its foreign staff from Yanbu. "Our people on the ground have had meetings with the employees who were there and asked them if they would agree to stay if we beefed up security, took it over ourselves, or whether they would prefer to leave. Not surprisingly, everybody wanted to go home," ABB spokesman Bjorn Edlund told The Associated Press. ABB has made plans to evacuate more than 100 employees and their families over the next couple of days, he said. He declined to give further details. Staff from ABB-Lummus, which is headquartered in Houston, had been working on a project to extend and revamp an ethylene plant for Exxon Mobil and the Saudi company SABIC. It was due to be completed in September. "The project will have to stop for a while. Safety is our priority," Edlund said. He said many of the staff working on the project were Americans but there were also workers from Britain, Australia, the Philippines and India. **PHOTO CAPTION*** A video grab shows Saudi police standing near a burned vehicle in the Saudi oil and petrochemical hub of Yanbu on the Red Sea, May 1, 2004. (Reuters)