Iran's powerful Revolutionary Guard has revealed footage of a secret missile base in an underground tunnel deep in a mountain side.

The video, aired on semi-official Fars TV and set to rousing music, shows an extensive tunnel packed with medium- and long-range missiles and launcher units.

The Guard said the missiles were on their launch pads, ready to be fired in the event of an attack on the country.

The video shows what appear to be officers walking over flags of Israel and the United States painted on the floor.

The broadcast did not disclose where the base is, but said it was 1,600ft (500m) underground.

It also claimed the base was one of hundreds in the country.

During the broadcast, Amir Ali Hajizadeh, head of the Guard's aerospace branch, said the facility was "only the tip of the iceberg".

"We have so many bases that (our enemies) cannot confront those bases, no matter how many bases they identify," he said.

"There are only few provinces, cities or towns (across Iran) without at least one missile base."

The broadcast appeared to be aimed at showing the Guard will continue its missile programme - despite the country's nuclear deal with world powers and UN Security Council resolutions.

At the weekend, the Guard also fired a new long-range, surface-to-surface missile which the US claimed may have breached Security Council resolutions.

The base tour and the missile launch suggest Iranian hard-liners will remain a potent force in the country as it gives the final approval to the nuclear deal.

The Guardian Council's approval, in the face of attempts by opponents to derail the deal, is a major victory for moderate President Hassan Rouhani, who campaigned on calming tensions with the West.

The landmark deal requires Tehran to limit its nuclear programme in return the easing of international sanctions.

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