NICOSIA, Aug 31 (Reuters) - Nearly 20 people were missing on Monday after a ferry capsized off northern Cyprus, killing at least eight, as divers joined search teams scouring deepwaters for any survivors.The double-hulled ferry with 267 aboard took in water and flipped over on Sunday just off the port city of Kyrenia, leaving survivors clinging to the overturned hull. They were rescued by passing vessels and the coastguard authorities."We've been waiting since the morning, for 12 hours or maybe more," said Naif Ezer, one of those waiting anxiously outside the port for news of passengers through the early hours of Monday.Of three friends traveling home to see families, one had been found but the other two were still missing, he added.Some of those waiting sat and silently wept, while others scrolled mobile phones for updates.It was unclear if people remained trapped on the vessel, now lying on the seabed at a depth of more than 500 m (1,640 ft).Divers from Turkey were assisting the search, officials said. They gave differing estimates of the missing, with some saying 19, and others 18.The ferry ran into trouble shortly after leaving Kyrenia for the Turkish port of Tasucu in Mersin province, one of several daily sea shuttle links with Turkey.Separate accounts said the wide-bodied vessel jolted violently before slamming onto the sea surface, with part of its bow bursting open on impact.Authorities have detained the captain and crew of the vessel for questioning. (Reporting by Mehmet Emin Caliskan and Ali Kucukgocmen; Writing by Michele Kambas; Editing by Clarence Fernandez)