UN monitors have arrived in Pyongyang, North Korea, to keep watch over the nuclear complex at the heart of a disarmament deal.
The six experts from the International Atomic Energy Agency take the place of some colleagues already at North Korea's Yongbyon complex.
In February, North Korea agreed to close the reactor in return for 50,000 tonnes of heavy fuel oil.
Earlier this month, the UN nuclear watchdog confirmed that North Korea had shut down its nuclear reactor and four related facilities in what was seen as a major step in efforts to get the country to give up its nuclear weapons programmes.
The Yongbyon reactor produced material that could be turned into weapons grade plutonium.
The new group of monitors will stay in North Korea for two weeks.
