The Revolutionary Guards said in a statement that the tests demonstrated the country`s "deterrent power" and "ability to confront any threat".

In January, the US imposed sanctions targeting Iran`s missile programme in response to the last round of tests.

UN experts said those tests had violated a Security Council resolution.

The resolution, which barred Iran from undertaking any work on ballistic missiles capable of carrying nuclear warheads, expired after a nuclear deal between Iran and six world powers was implemented two months ago. A new resolution then came into force that "calls upon" Iran not to undertake such activity.

Iran says it does not have nuclear weapons and will continue missile development.

`Appropriate response`

Iranian state television reported on Tuesday that the missiles were fired from silos at various locations, without naming them.

It broadcast pictures of one of the night-time launches, and a presenter said the missile was a medium-range Qiam-1, according to the Reuters news agency.

The Revolutionary Guards` statement said the tests were intended "to show Iran`s deterrent power and also the Islamic Republic`s ability to confront any threat against the [Islamic] Revolution, the state and the sovereignty of the country".

The head of the Guards` Aerospace Force, Brig Gen Amir Ali Hajizadeh told state television that the missiles had "struck a target 700km (435 miles) away".

He warned the US was "trying to turn off the lights of Iran`s missile programme", adding: "The Guards don`t give into threats."

A US official told Reuters that there were "strong indications" that the tests were inconsistent with the new UN Security Council resolution, and that if that was confirmed Washington would seek "an appropriate response".

"This development underscores why we continue to work closely with partners around the world to slow and degrade Iran`s missile programme," the official said.

While any missile of a certain size could in theory be used to carry a nuclear warhead, Iran says its missiles are for use solely as a conventional deterrent.

It claims to have ballistic missiles with a range of 2,000km (1,250 miles) that would be capable of reaching Israel and US military bases in the Middle East.

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