VIENNA, March 27: United Nations nuclear inspectors arrived in Iran on Saturday, an IAEA spokeswoman said, in what is an ongoing investigation to determine whether the Iran is secretly developing atomic weapons , as Washington accuses it of doing.

Iran had tried to put off the mission earlier this month after the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA), condemned it for continuing to hide sensitive nuclear activities.

But Tehran yielded and allowed the visit after a delay of two weeks, following an international outcry against Iran for failing to cooperate with the atomic agency.

The two-man IAEA team, which arrived early Saturday in Tehran after flying from IAEA headquarters in Vienna, was already on its way on Saturday to the Natanz uranium enrichment plant, 250 kilometres south of Tehran.

The inspectors will also visit the Isfahan nuclear technology centre, in what is a regular inspection on monitoring safeguards set up under the nuclear Non-Proliferation Treaty (NPT), spokeswoman Melissa Fleming said.

More aggressive inspections are expected later in April, diplomats said.

Meanwhile, IAEA chief Mohammed ElBaradei is to visit Iran in early April to urge Iran to cooperate fully in answering questions about its nuclear programme, Fleming said.

It will be Elbaradei's third visit to Iran since the IAEA began in February 2003 to verify whether Iran's nuclear programme is peaceful, or devoted to secretly developing atomic weapons, as the United States claims.-AFP