Peugeot 306 front flashing lights - starter changed and disconnected?

Hi, I recently changed the starter on my P reg 306 and when the battery was reconnected the front light flash for about 30 seconds when i open the door, start the car and close the door.

I think this may have something to do with the alarm but there is no sound and i dont have the key for bit under the bonnet ( immobiliser possibly), there is also no keyfob.

The car starts fine when the code is entered but the lights flash, if i turn the lights on then they stop flashing but you can still hear the clicking noise as if the hazards are on, for about 30 seconds, the flashing stops and only returns if i open the door or turn the car of and start it again.

hope this makes sense and i hope someone can help, is there a sequence to reset this?

Gary - jesusjones13@hotmail.com