Iran has invited envoys from developing nations accredited to the UN nuclear watchdog to visit its nuclear sites in a show of openness about its atomic fuel programme, diplomats said. Tehran has invited envoys from the Non-Aligned Movement (NAM) of developing nations attached to the IAEA, and heads of the larger Group of 77 states and of the Arab League office in Vienna, to visit on Feb 2-6, an Iranian diplomat said. “They have been invited to visit our nuclear installations from the 2nd through the 6th,” the diplomat, who asked for anonymity, said on Tuesday. He did not elaborate.