Britons issued travel warning for 16 countries amid 'serious concerns' as popular tourist hotspots like Cyprus and Egypt affected

Officials cited "serious concerns" regarding escalating regional instability as the basis for the guidance.

The Foreign Office stated: "There is a heightened risk of regional tension. Escalation could lead to travel disruption and other unanticipated impacts.

"British nationals should take sensible precautions, considering their own individual circumstances."

The affected destinations collectively draw hundreds of thousands of British visitors annually, with Dubai alone welcoming approximately 16 million international travellers each year.

The warning followed Iran's abrupt decision to close its airspace to commercial aircrafts in the early hours of Thursday, offering no explanation for the move.

The shutdown affected a vital East-West flight corridor for more than four hours, compelling international carriers to divert their routes around Iranian territory.

Operations resumed shortly after 7am local time, with domestic flights beginning to take off once more.

SafeAirspace, which monitors aviation risks in conflict zones, cautioned that the closure could indicate imminent "security or military activity."

"The situation may signal further security or military activity, including the risk of missile launches or heightened air defense, increasing the risk of misidentification of civil traffic," the organisation warned.

Tehran previously closed its skies during last June's 12-day conflict with Israel.

Concerns are mounting that potential military intervention by President Trump against the Iranian regime could trigger a broader regional conflagration, heightening risks of violence and severe travel disruption.

The tensions stem from Tehran's brutal suppression of nationwide protests, which has claimed at least 2,615 lives according to the US-based Human Rights Activists News Agency.

Donald Trump left observers guessing on Wednesday with ambiguous statements about possible American action, having previously assured Iranian demonstrators that "help is on the way."

Iranian foreign minister Abbas Araghchi responded with a plea for dialogue.

"Between war and diplomacy, diplomacy is a better way, although we don't have any positive experience from the United States. But still diplomacy is much better than war," he told Fox News.

The Foreign Office has also highlighted the threat of terrorist attacks in the UAE, warning that extremists may specifically target British nationals and Western interests in Dubai.

"Terrorists continue to issue statements threatening to carry out attacks in the Gulf region," the department noted, advising travellers to remain vigilant at all times.

Meanwhile, US military movements in the Gulf have intensified, with selected personnel at an American base in Qatar ordered to depart.

The US Embassy in Kuwait has simultaneously instructed staff to temporarily suspend visits to military installations across the country.