"We signed the players upon the recommendation of head coach Carlos Cabral," Ittihad director Mohamed Fathi told FilGoal.com.
Defensive midfielder Klein, 24, joins Ittihad after his contract with Brazilian third-division side Brasil de Pelotas expired.
Striker Mora, 26, ended a spell with Novo Hamburgo, who also play in the third division.
His arrival comes few hours after Brazilian coach Cabral expelled Ittihad's top scorer Mohamed Ragab from the team's training camp for disciplinary reasons.
"Ragab left the camp without permission more than once. Cabral is fed up with his actions," Fathi said.
The former Olympic striker, who scored five goals so far this season, insisted Cabral was mistreating him.
He said he might leave the club before the end of the January transfer window.
Ittihad, who usually struggle at the wrong end of the league table, have enjoyed a revival since the appointment of Cabral last September.
A nine-match unbeaten streak helped them move up to ninth before the winter break.