CAIRO, June 19 (Reuters) - The memory units of both flight recorders from crashed EgyptAir flight MS804 are severely damaged and will require "lots of time and effort" to fix, Egyptian aircraft accident investigation committee sources said on Sunday.

The committee is analysing the memory units from the Cockpit Voice Recorder (CVR) and the Flight Data Recorder (FDR) before determining if they can be repaired in Egypt or will need to be sent abroad.

Search teams retrieved the CVR on Thursday and said at the time that they found it damaged but that the memory unit was intact. They found the FDR on Friday.

The two black box recorders are crucial to explaining what went wrong on the Airbus A320, which crashed early on May 19 on its way from Paris to Cairo killing all 66 people on board.

The crash is the third blow since October to Egypt's travel industry, which is still suffering from the 2011 uprising that ended Hosni Mubarak's 30-year rule.

A Russian plane crashed in the Sinai Peninsula last October, killing all 224 people on board in an attack claimed by Islamic State. In March, an EgyptAir plane was hijacked by a man wearing a fake suicide belt. No one was hurt.

(Reporting by Ahmed Aboulenein; Editing by Richard Balmforth) ((ahmed.aboulenein@thomsonreuters.com; +20 2 2394 8097; Reuters Messaging: ahmed.aboulenein.thomsonreuters.com@reuters.net))