Thousands of villagers staged a protest outside one of South Korea's largest nuclear power plants Thursday, voicing growing public concern over safety standards after a series of scares and scandals.

Yonhap news agency said 2,500 local villagers took part in the protest outside the Yeonggwang complex on the southwest coast, where three of the plant's six nuclear reactors are currently in shutdown.

Media photos of the event showed protesters burning an effigy representing the state-run nuclear operating agency KHNP and holding up placards saying: "We feel uneasy!"

They are calling for an overall safety review of the plants.

Hundreds of riot police and security officers were sent to the demonstration but there were no reports of any violence.

Last week, the government shut down two reactors at Yeonggwang to replace thousands of "non-core" parts that had been provided with forged quality and safety warranties.

The shutdown prompted authorities to inspect components at all of the 23 reactors nationwide, which generate around 35 percent of the country's electricity.

The Nuclear Safety and Security Commission also extended the closure of a third Yeonggwang reactor after minor cracks were found during maintenance work on control rod tubes.

Although KHNP officials insisted there had never been any threat of a radiation leak, the incidents stoked safety concerns heightened by last year's nuclear disaster in Japan.

The South Korean government has vowed to stick to its nuclear power programme despite the Fukushima crisis, and plans to build an additional 16 reactors by 2030.

Last month, authorities temporarily shut down two 1,000-megawatt reactors at separate nuclear plants after system malfunctions which were also blamed for another reactor at Yeonggwang being tripped into automatic shutdown in July.

In May, five senior engineers were charged with trying to cover up a potentially dangerous power failure at the country's oldest nuclear plant.

The Gori-1 reactor, built in 1978 near the southern city of Busan, briefly lost mains power on February 9 and the emergency generator failed to kick in. The power cut caused cooling water to stop circulating.

The government has warned that the current shutdown of the three Yeonggwang reactors could result in serious power shortages during the harsh South Korean winter.