South Korea will hold military drills near the border with North Korea this week against a background of simmering tensions with its communist neighbour, an official said Sunday. The South\'s army will stage field training exercises in the city of Paju from Monday to Friday, Seoul\'s defence ministry spokesman said. \"The training is something we have been doing on a regular basis to improve our combat readiness,\" he said without elaborating. Cross-border tension has been acute since the North\'s alleged sinking of a Seoul warship that claimed 46 lives and a shelling of a frontier island that killed four South Koreans last year. Ties deteriorated again after Pyongyang announced late last month it was breaking all contact with Seoul\'s conservative government, which has demanded an apology from the North over the two attacks. The arrival by boat in South Korea of nine refugees from the North this month has further heightened tensions after Seoul rejected Pyongyang\'s demand to send the nine back. A Seoul-based group of North Korean defectors launched 100,000 anti-Pyongyang leaflets across the border on Saturday urging the toppling of the communist regime, despite threats from the North to shoot at them. Giant balloons were inscribed with anti-Pyongyang slogans including one calling for the overthrow of leader Kim Jong-Il and his youngest son Kim Jong-Un\'s \"hereditary dictatorship\".