At least eight migrants have drowned after their boat sank following a crash with a Tunisian navy vessel in the Mediterranean, the defence ministry said Monday.

Eight bodies were found and 38 people rescued after the unidentified boat "collided with a military vessel" Sunday evening when it was approached some 54 kilometres (33 miles) off the islands of Kerkennah, ministry spokesman Belhassen Oueslati said, adding search operations were continuing.