A rocket has been fired at a car carrying the deputy chief of the British diplomatic mission in Yemen.
Officials say a member of staff has been injured, but not seriously.
Three bystanders in the Yemeni capital, Sanaa, were also hurt.
It has long been feared that al-Qaeda plan to use Yemen as a base from which to launch attacks in the region and beyond.
In a separate incident, the head of the Yemeni branch of the Austrian oil and gas company OMV was killed when a security guard opened fire at the company compound in Sanaa this morning.
The gunman was disarmed by government security forces.