North Korea on Thursday expelled 11 South Korean government officials working in the Kaesong industrial park on the northern side of the heavily armed border in an angry response to moves by Seoul to toughen its approach to the communist state.

The expulsions follow international pressure on the North to make a full ­declaration of its nuclear programmes and calls by Lee Myung-bak, the South’s newly elected conservative president, for action on the sensitive issues of prisoners of war and abductees.