Lakuri pirates are mentioned in the 2nd Lone Wolf book ''Fire on the Water''. The text says exactly: ‘Twenty-five years at sea and I’ve never known the Lakuri pirates to venture this far north to raid,’ he says, stroking his beard thoughtfully. ‘They must be after a valuable cargo to sail so far from their tropical islands.’
This implies that Lakuri pirates live in some tropical islands far south from the sea of Sommerlund; where this encounter takes place.