South Korea's military has raised its alert against potential cyber-attacks from North Korea after the death of leader Kim Jong-Il, the defence ministry said Tuesday.
The ministry raised the alert level called Infocon from the normal peacetime level of five to four immediately after Kim's death was announced Monday, a ministry spokesman told AFP.
"All related officers are on higher alert and monitoring the situation very closely," he said.
The military has doubled the number of officers monitoring any attempts at hacking or DDOS (Distributed Denial of Service) attacks on its online systems, Yonhap news agency said.
The North maintains elite hacker units, prompting the South to set up a specific military command to combat them.
In May South Korean prosecutors said the North's military intelligence had launched a cyber-attack that paralysed operations at one of the country's largest banks.
Seoul also accused Pyongyang of staging cyber-attacks on websites of major South Korean government agencies and financial institutions in March this year and in July 2009.
Pyongyang said Seoul invented the charges to raise tensions.
The South's telecommunications regulator, the Korea Communications Commission, also raised its alert against potential online attacks after the shock announcement of Kim's death.
Explore further: China blocks VPN services that skirt online censorship