The trial of three BBC television journalists charged with filming in Yemen without government permission, has opened in the capital, Sanaa.

Court officials said the judge heard the charges against the three men, who include the BBC correspondent, Rageh Omaar.

They were arrested last month after returning from a remote area of Yemen where a tribe has kidnapped several foreigners.

The BBC says the journalists were properly accredited, and has appealed for them to be allowed to return home.