anti pollution fault on a c5 petrol?

hi all
while driving my 2002 2.0l petrol citroen c5 with 69k on the clcok the warning flashed on the display screen (anti-pollution warning) and the engine managenment and service symbols came on the dash, i stopped and turned off the engine and started it again but all the warnings stayed on.
i decided to drive to my home which was only 3/4 miles away.i started the engine again after about 2 hours and all the warning symbols had gone and still have not came back on. can anybodytell me if its ok to drive as i dont want to do any damage as the car is still in very good condition.
many thanks jp

jp
November 2010