Seoul: In a bid to prevent any kind of attack by the North Korean agents, South Korean troops on Wednesday staged a rare exercise to guard its nuclear power plants, the Defence Ministry said.

The drill involving hundreds of soldiers, anti-terror police, firefighters and government officials took place at the Gori complex on the southeast coast, the ministry said.

The plant has four reactors, including the first one built in 1978, and four more are under construction.

The drill inspected by Han Min-Koo and chairman of the Joint Chiefs of Staff simulated the infiltration of North Korean agents to bomb a nuclear power plant, a ministry spokesman informed.

"Our nation will face a very dangerous situation in case of emergencies of any kind at nuclear power plants," Han said in a statement, calling for "perfect disaster preparedness".

The nuclear crisis in neighbouring Japan has already prompted South Korea to run safety checks on its own plants. South Korea operates 20 nuclear plants, which generate some 35 percent of its electricity needs, and plans to build 12 more over the next 14 years.