The risks they face are real and constant - suicide bombs, improvised explosive devices and gunmen clandestinely embedded in the Afghanistani armed forces.

This week's murder of eight South African aviation personnel has brought that stark reality home.

The eight - who worked for aviation chartering company Aircraft Charter Solutions/BalmOral, - were killed early on Tuesday as they drove towards Kabul International Airport to fly high-profile BalmOral clients to an undisclosed destination.

A 20-year-old woman drove her car, packed with explosives, into their vehicle, killing them instantly.

Among the dead were Brandon Booth - whose girlfriend gave birth to a daughter, Willow, two months ago - Fraser Carey and Johan Bouchaud, both of whom were engaged to be married.

According to company sources, BalmOral has been contracted to the Nato-led International Security Assistance Forces for the past eight years. It is responsible for transporting diplomats and security personnel across Afghanistan.

A BalmOral staff member who has served several "tours" to Afghanistan described it as "hell on earth".

Asking not to be named because he is not authorised to speak to the media, he said: "There, everyone wants to kill you. These guys are lucky in a sense - they did not suffer.

"Make no mistake, that place is not a joke. It is a not a Hollywood war movie. It is very real and very dangerous. Not even in your base are you safe."

The most dangerous time was when travelling.

"That is when you are vulnerable. Like with this bombing. You never know when it is coming or where it is coming from. It can be a bomb hidden in a car or a 'pregnant' woman walking alongside the road," he said.

The only reason South Africans went to work there, he said, was for money.

"There are adventurers among us, but they also go for the money. The money is very, very good."

But it comes at a high cost.

"Every day is a death sentence and coming home is the reprieve given by the warder at the last moment."

A source close to the pilots said all of the staff were concerned about security.

"The danger increased because of this anti-Islamic video, but there were other concerns about the way things were done."

Despite the risks and threats, all of the pilots had chosen to carry out their contracts, he said.

Carey's flying partner and close friend, Vladimir Milosevic, said they had met in Algeria while on a flying contract for an oil company.

"This feels surreal. We all know the dangers when you go to places like Afghanistan, but you never expect it to happen. You keep it pushed at the back of your mind," he said.

Milosevic described Carey as a "happy-go-lucky dude, with his head always in the clouds".

"He, like the rest of his friends there, were full of life. He was an extremely optimistic person who always saw the positive in every situation, no matter how bad it was."

Attempts to get comment from BalmOral CEO Sej Dunning, who is due to fly to Afghanistan, proved fruitless.

THOSE KILLED INCLUDED:

Pilots Fraser Carey, 31, Brandon Booth, 47, and Johan van Huyssteen, 31.

Engineers Christian Pretorius, 30, Johan Bouchaud, 30, Johannes Humphries, 65, and Steven Leong, 31.

Public relations operations controller, Jenny Ayris, 47, a Scot who had dual South African citizenship.