A police officer was killed in a drive-by shooting in the outskirts of the Tunisian resort of Sousse on Thursday.
Two men on a motorbike armed with a rife opened fire on three policeman.
One died on the way to hospital and the other two were unhurt.
Tunisian officials have launched a major search operation.
The shooting comes less than two months after a gunman opened fire on a beach in the resort, killing 38 people including 30 British holidaymakers.
Following the attack, the Foreign and Commonwealth Office imposed a ban on all but essential travel to Tunisia.
The Tunisian government reinstated a state of emergency and on July 31 this was extended for a further two months.
UK tour operators and airlines have cancelled flights and holidays to Tunisia.
Thomas Cook and First Choice have cancelled flights to Tunisia until March 22 2016 and earlier this week Thomas Cook confirmed it was cancelling its Tunisia programme until February 13.
