British expatriates working in Saudi Arabia have been shocked by the killing of foreign hostages by gunmen in the city of Khobar.
Vehicles were left riddled with bullets
Several who talked to BBC News Online say they are considering quitting the oil-rich state amid what they see as a worsening security situation.
Briton Paul Raven, 50, an operations manager, said: "Expats working here are getting scared and they are leaving."
Mr Raven, who supervises the running of supermarkets on residential compounds in the eastern city, has spent 10 years working in Saudi Arabia.
He said: "People feel very vulnerable and apprehensive and I think we will now see a lot more people go.
"This event has shaken people as the Oasis compound, where the gunmen struck, is one of the most secure.
"Even as an expat, I have found it difficult to get on and off site there, but the security has not prevented the gunmen getting in.
"We have national guards looking after us, but the gunmen were all dressed as them."
Mr Raven says the number of British expats working in Khobar has dwindled.
"The Riyadh bombings made a lot of people rethink what they were doing and they left. Life has changed a lot and we are constantly wary of security.
"We travel to work at different times and vary the routes we use to get there."
Originally from Bath, Somerset, Paul and his wife were living together in Khobar, but she has left because of the worsening security situation.
They now see each other when Mr Raven goes back to the UK on leave, but she has refused to return to the Arab country.
"I have a 22-year-old daughter at home and a son of 20, and my wife has called me from the UK since this incident and said: 'Look, it's just not worth it, you need to come back.'
"It is a great shame. We had a very nice life here five or six years ago, with people travelling around freely to meet up and socialise and play sport, but you just can't do that any more. People will not go off-compound.
"I now have to consider leaving, as things are only going to get worse."
Fourteen-year-old Barbara Mandich, who attends a British school in Khobar, e-mailed BBC News Online to say: "We were only informed of the shootings at about 10 this morning.
"The staff tried to keep it hidden from us so that we could all stay calm."
But she said older students told her and her school friends about the shootings.
She added: "Rumours came and went and we sat in class getting text messages from our parents and friends on the compounds where all the shooting was happening.
"It was hard to distinguish truth from rumour and everyone was left scared and worried.
"None of us knew what was really happening, we just prayed to God that it was nothing bad.
"Now we all sit at home calling all our friends to see if everyone is alright - most of the schools, including mine, have been closed.
"Many westerners have decided to leave the country altogether."
Colin Hewetson, who works in the oil and gas industry like most British expatriates in Saudi Arabia, told BBC News Online many people were seriously considering the risks of staying on.
"The Saudi security forces are doing a very good job given the circumstances - the expat compounds are pretty well guarded by security troops.
"But we have to consider whether we should come back to the UK or stay."
Mr Hewetson, 58, has been living in Saudi Arabia for three years but says things considerably worsened after two suicide attacks in Riyadh in May and November last year which left scores of people dead.
"Before the attacks, it was a quiet life, but since the Riyadh bombing everybody is very careful.
"We have to check out our cars before we get into them... that's life here these days, you just have to be careful."
"Obviously if we had our children here we might have left earlier. But they are in the UK, like the children of most expatriates here."
He said he talked to some friends and colleagues after the attacks on Saturday, and many who were leaving for their summer holidays said they would not come back.
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