It is a story of strong tribal allegiances and a weak central government, which is the typical background to the kidnapping of more than 100 foreigners in Yemen in the Nineties. It also shows the difficulties facing negotiators who are trying to persuade the kidnappers to free Mr and Mrs Rosser along with Hans Koolstra, a Dutch aid worker, and his family.
It started when two men walked into the grocery store owned by Garyah al-Rayami on the airport road in the al-Jaraf district of Sanaa.
The street looks like any other in the city, with small shops facing the street and the gutters filled with rubbish. Less obvious is the fact that the district is controlled by the powerful Bakhil tribe, to which Mr Rayami's customers belonged.
There are two versions of his murder. The official one is that the two Bakhil tribesmen, one a relative of its ruling sheikh, asked for an item on a high shelf in the shop. Mr Rayami, who had recently lost pounds 50 to thieves, would have had to fetch a ladder to reach it, leaving his shop unattended for a moment. He refused to serve the two men. A quarrel started and one of the men shot Mr Rayami dead.
A simple, if brutal tale, but his neighbours have a different explanation of what happened. They say the two men from the Bakhil tribe were collecting protection money from non-Bakhili shopkeepers in the district and Mr Rayami, who did not belong to the tribe, refused to pay up and they killed him.
The alleged murderers were arrested, and it is the dropping of the charges against them which is the chief demand of the kidnappers.
The Rosser and Koolstra families were seized on 17 January by other members of the Bakhil, most of whom live in their mountain redoubt north of Sanaa.
Curiously, one of the men accused of the crime is not in jail. It is a measure of the weakness of central government in Yemen that important people - and a relative of Sheikh Abdul-Aziz al-Shaef, the Bakhil's paramount leader, is very important - can hire a substitute to stay in prison in their stead when they are on remand. Nevertheless, the kidnappers want the government to drop the case.
Mr Rayami's family, who come from a village west of Sanaa and have no powerful protectors, are demanding that the murderers be executed.
Walking down the street where Mr Rayami died, it is difficult to believe that his relatives will get the justice they demand. His shop is shuttered and closed. It has two padlocks on the metal grille, one put there by the local sheikh and one by the dead man's family. Outside it lounge six well-dressed and heavily armed Bakhil tribesmen.
The message seems to be that if the family does not accept blood money rather than insist on a trial, they will not get the shop back.
Enquiries among local people about the murder of Mr Rayami are not welcome. "Are you a journalist or an investigator?" asked one hostile shopkeeper, openly fingering his pistol. "Careful, or I'll call the boys from across the road," he said, adding: "I am a Bakhil. I don't want anything to do with the government."
Not all of Sanaa is so wholly ruled by a single tribe, though they are stronger in the city than they used to be. One local businessman said: "Twenty-five years ago tribesmen had to give up their sub-machine-guns at checkpoints around the city. Now everybody carries one. I have one myself under the seat of my car for protection."
The government contends privately that the power of tribes such as the Bakhil and its influential neighbour the Hashid is not just the sign of an under-developed society. Both receive large monthly subsidies from the Office of Yemeni Affairs, which is part of Saudi Arabia's Ministry of Defence.
Most Yemenis believe that Saudi Arabia wants to keep Yemen, its historic rival in the Arabian Peninsula, weak by financing the tribes. They also see the kidnaps as serving the Saudi aim of keeping Yemen diplomatically isolated.
Unfortunately for Mr and Mrs Rosser and the Koolstra family, the tribes have learnt that when it comes to putting pressure on the government, nothing is as effective as kidnapping foreigners.
The five Britons and one man using a French passport arrested last month in Yemen and charged with planning an Islamic guerrilla campaign there will be put on trial on Wednesday, a Yemeni official said yesterday.
Yemen said the six men have admitted possessing illegal weapons and intending to commit murder. But the men's lawyer said they had denied the charges.Reuse content