Police and security guards from Cambodia's "Killing Fields" tribunal arrested former Khmer Rouge Foreign Minister Ieng Sary on Monday, the third Pol Pot henchman to be taken into custody by the UN-backed court.

The octogenarian, who became the international face of the Beijing-backed ultra-Maoist revolution after it was overthrown by a 1979 Vietnamese invasion, will be charged with crimes against humanity and war crimes, a tribunal statement said.