British Airways' (BA) decision to suspend flights to Saudi Arabia has caused consternation among Saudi officials.
By Liam McSheffrey
"It's absolutely unwarranted," said Jamal Khashokji, an adviser to the Saudi Ambassador in London, Prince Turki el-Faisal.
Passengers don't know how long the disruption will last
However the decision comes amid rising tension in the desert kingdom stretching back to the Riyadh suicide bombings on 12 May which left 35 dead.
Saudi security forces have been fighting pitched battles with Islamic militants inside the kingdom.
They have uncovered what they call terror cells linked to the al-Qaeda network.
On Tuesday there was a shootout in Riyadh which killed five people and a gun battle at a farm in July killed eight.
It is against this background that the Saudi authorities have been trying to tackle the problem of Islamic militants inside their country.
But from where did the intelligence come which prompted Britain to advise its national carrier to suspend flights?
It came from Saudi intelligence.
They were literally watching Riyadh airport and their officers discovered that militants also had it under surveillance.
Saudi Arabia is still said to be bewildered by the decision to suspend flights.
"Unless there are intelligence reasons for the decision of BA, it remains unjustifiable," said Jamal Khashokji.
"We hope to hear more details about this from the British."
Even before this latest development, relationships between the US, Britain and Saudi Arabia were strained.
Last week the Saudi authorities released five Britons convicted of carrying out a wave of bombings in the Gulf state in 2000 and 2001.
Families of the jailed men had always maintained that local militants were responsible.
Then, in July, Saudi Arabia was outraged that part of a US congressional report into the 11 September attacks had suggested links between some of the hijackers and high-ranking Saudis.
Saudi Arabia flatly denies this suggestion.
It says Western countries always seem to forget their efforts to fight terrorism, and the fact that it provides intelligence which has led to the arrests of leading militants in such countries as the US.
But both the US and British governments have made the safety of their nationals around the world a top priority since 11 September.
"Events of this nature are always difficult but that never stops us from taking the appropriate action, which is always with regard to the safety of our customers and our staff," said BA spokesman Geoff Want.