North Korea says it has removed seals from its atomic facility as part of its plan to re-start its nuclear operation, according to media reports.

A government spokesman said that work to restore and reactivate operations at Yongbyon were under way, the Kyodo News Agency reported.

"Seals have been taken off," a senior diplomat close to the IAEA said on Monday.

Earlier, the International Atomic Agency (IAEA) said that Pyongyang had asked to remove the seals and surveillance cameras that had been put in place to prevent the site being used.

"This morning [North Korea] asked the agency's inspectors to remove seals and surveillance equipment to enable them to carry out tests at the reprocessing plant, which they say will not involve nuclear material," Mohamed ElBaradei, the IAEA director, said at a UN meeting.

North Korea said on Friday that it was working to restart the Yongbyon complex which is used to produce plutonium, the basis of its atomic bomb programme.

It abandoned its decommisioning efforts last month, saying that the US had failed to keep its part of the deal on freezing nuclear activity.

Energy aid

South Korea's Foreign Ministry said that Pyongyang could lose out on energy aid if it continues restoring its Yongbyon nuclear reactor.

"If North Korea continues its restoration activities, the economic and energy aid in line with disablement will have to be affected,'' Moon Tae Young, South Korean foreign ministry spokesman, told reporters in Seoul.

North Korea was promised one million tonnes of heavy fuel oil or equivalent energy aid in return for disabling its nuclear reactor.

Work to disable Yongbyon began last November and in June, the main cooling tower at the plant was demolished in what was seen as a sign of the North's commitment to the disarmament process.

In the same month, North Korean officials handed the US a list of its nuclear programmes and facilities in return for what it says was a promise that Washington would start the process of removing North Korea from the US "terrorism" blacklist.

Washington has refused to begin that process until the North agrees to an international plan to verify the nuclear declaration.

As a result North Korea announced in mid-August that it was calling a halt to disablement work at Yongbyon.