Updated: Series of rallies held for Johnston

The BBC has held a series of rallies across the UK for its missing correspondent Alan Johnston.

Johnston was kidnapped in Gaza on March 12. Last night, group calling itself the Al Tawhid Al Jihad brigades ("Brigades of Holy War and Unity") faxed numerous news organisations with a claim that it had killed Johnston. The BBC, Foreign Office and Palestinian authorities have each said they are investigating the claim but that at the moment it is an unsubstantiated rumour.

In a statement at lunchtime, the BBC said: "Since Alan's disappearance, gatherings have taken place every Monday afternoon at the BBC's Television Centre and Bush House. These, together with events at other BBC locations, will take place again today at 2.15pm."

This afternoon, BBC director general Mark Thompson addressed staff at Television Centre. Richard Sambrook, the corporation's director of global news, did the same outside Bush House, current home of the World Service.