South Carolina Governor Jim Hodges has declared a state of emergency and placed troopers on the state's borders in an attempt to block federal shipments of plutonium.

"I order that the transportation of plutonium on South Carolina roads and highways is prohibited," Mr Hodges was quoted by the Associated Press news agency as saying.

"I order that any persons transporting plutonium shall not enter the state of South Carolina."

His decision follows a refusal by a US federal judge to block the shipments of weapons-grade plutonium by the US energy department from a site in Colorado....