Vienna  - The International Atomic Energy Agency (IAEA) increased its pressure on Iran to prove it had not conducted nuclear weapons-related work, in a report published Friday that confirmed a slight decrease in the country's enrichment activities.

In his latest report, IAEA chief Mohamed ElBaradei also said Iran had partly improved its cooperation with the Vienna-based agency by allowing better monitoring at its controversial enrichment facility in Natanz, and by allowing a visit to a reactor that is under construction.

The IAEA has been trying to shed light on documents related to past Iranian studies and research projects in which military entities were involved.

"In the light of the above, the agency has repeatedly informed Iran that it does not consider that Iran has adequately addressed the substance of the issues (...)," ElBaradei concluded.

Concerning uranium enrichment, the IAEA said some 4,600 centrifuges were operating in Natanz on August 12, slightly less than reported in its June report.  (dpa)