By firing ballistic missiles at the UK-US Diego Garcia base nearly 4,000km (2,485 miles) from its shores, Iran is sending a message that it still has cards to play after three weeks of war, according to experts.

A UK official source said Iran was “unsuccessful” in targeting the Indian Ocean military facility, one of two bases that London has allowed the US to use for certain missions in its war against Iran.

Until now, most had believed Iran – under US-Israeli bombardment since February 28 – was unable to strike at such distances, though the feat was unlikely to alter the course of the conflict.

The launch “is a notable development, since the British island used by US forces lies nearly 4,000km from Iran’s coast”, researcher Etienne Marcuz of the French Foundation for Strategic Research said on social media.

That is “beyond the previously estimated maximum range of Iranian missiles”, he added.

Previous assessments put Iran’s medium-range ballistic missiles (MRBM) at around 3,000km.