VIENNA - A US security institute published new satellite imagery on Wednesday which it said appeared to show further activity to clean up an Iranian military site which the UN nuclear watchdog wants to inspect, including removing earth.

Parchin, which Iran says is a conventional military complex, is at the center of Western allegations that Iran has conducted experiments - possibly a decade ago - that could help develop atom bombs. Iran denies any such ambition.

The Institute for Science and International Security (ISIS) published the latest satellite picture a day after Iran and six world powers failed to make any progress on their decade-old nuclear dispute during two days of talks in Moscow.

Iran has so far refused to grant the International Atomic Energy Agency (IAEA) access to the Parchin facility as part of the UN agency's long-stalled investigation into suspected nuclear bomb research in the Islamic Republic.

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