Security companies operating in the Arabian Gulf are taking British guards off the ships they’re protecting over fears Iran could try to detain UK nationals. It comes amid heightened tensions in the region and Iran’s seizure of the UK-flagged tanker, Stena Impero, last month in the Strait of Hormuz. Tehran was also accused of sabotaging vessels in May in the Gulf of Oman although Iran denies this. Now some major maritime protection firms, including Maritime Asset Security and Training, the largest in the sector, are replacing UK nationals working in the Gulf with guards from other countries. "We have instigated a policy of no UK guards in the Gulf [We] are advising our clients the same," John Thompson, who co-founded the protection company Ambrey and is a former officer in the elite Parachute Regiment, told the <em>Financial Times.</em> Would-be Ambrey guards must meet an array of conditions to get on ship including a minimum four-year continuous military service and no previous criminal convictions. The UK foreign office continues to warn that UK nationals, and in particular British-Iranian dual citizens, are at risk of being “arbitrarily detained in Iran.” “British nationals, in particular dual British-Iranian nationals, face greater risks than nationals of many other countries. The security forces may be suspicious of people with British connections,” it says. Iran has also been accused of failing to uphold international standards in judicial processes. Earlier this week the UK announced it was to join a US-led maritime mission to “restore” safe passage in the Arabian Gulf. It has also tried but failed to convince European countries to take part in the coalition. The HMS Montrose and HMS Duncan are already assisting UK-flagged vessels through the Strait of Hormuz, the hugely important artery for the worldwide movement of oil and gas. The UK has said the seizure of the Stena Impero, none of whose crew are British, was “illegal” and a threat to commercial shipping. Iran says the move was a retaliatory measure over the British detention of an Iranian-flagged tanker off Gibraltar believed to be heading to Syria in violation of sanctions. US President Donald Trump has taken a particularly hard-line approach against Iran, re-upping sanctions on the regime and pulling out of the landmark 2015 deal that sought to limit Tehran’s nuclear capacity.