It is not just for UK citizens, told where to assemble to be airlifted to safety, that the BBC is crucial.

Bush House, home to the BBC's international broadcasting

Conducting audience surveys among Sierra Leone's 3-4 million inhabitants may be impossible, but African Service deputy editor Elizabeth Ohene was left in no doubt about the impact of BBC news and current affairs programmes during a recent visit.

"Wherever I went, everyone was listening - not just in Freetown but all over the country," she said.

It can be a pretty disconcerting experience, she recalls, when everybody you meet, from ordinary citizens to politicians to armed rebel troops, knows exactly who you are and what you have said in recent broadcasts.

Shhh! London's calling

The flagship African Service programmes are Focus on Africa and Network Africa, the daily news and magazine shows that are broadcast - afternoons and mornings respectively - from the World Service studios at Bush House in London.

"People tune in for every edition of Focus and every edition of Network," says the BBC African Service reporter in Freetown, Lansana Fofana.

"It's not like the whole of Freetown goes dead," he says. "But in areas where 10 or 15 people are clustered around radio sets, one person will get up and tell others 'Look, we're listening to the news so you'd better shut up'."

Role reversal

Evacuations were announced on the BBC

With such an impact, it is not surprising that the main players in the conflict are always keen to get their voices heard on the BBC, reversing the usual situation of journalists chasing politicians for interviews.

"They call us and we call them," Elizabeth Ohene says. "But you've got to be very careful of the consequences."

One example was when rebel leader Foday Sankoh phoned Bush House just as Focus was going on air and announced that his house was being attacked by an angry mob.

The producers decided not to broadcast the "scoop" without independent corroboration because, true or not, it would inevitably have led to an escalation of clashes in the capital.

Heavy burden

The impact of the BBC African Service's reporting in Sierra Leone, which is rivalled only by its reach in neighbouring Liberia, in fact puts an almost unbearable burden on the journalists concerned.

Disturbing news causes many to leave

"The responsibility is a bit too much," Elizabeth Ohene says, only half jokingly.

"The United Nations should have that kind of responsibility, but not the BBC."

But when it is not making the news itself, Lansana Fofana says the reliability of BBC journalism means it can act as an important influence on people's decisions, particularly if they are able to flee north to safety in Guinea.

"When they hear stories that are disturbing, you start hearing people say 'I'd better pack up and go because the BBC has just said the situation is this or that'."