Security sources told Reuters the detainees from the Muslim Brotherhood were aiming to plant explosive devices to disrupt shipping.
One of the arrested men is an employee of the canal authority.
Prosecutors have ordered they be held for 15 days.
Bombs had been planted in sanitation and electricity facilities, as well as on beaches, they added.
Last year, Egypt sentenced a group of 26 people to death for plotting terror attacks on ships in the canal.
A Cosco containership was attacked by terrorists as it transited the waterway in August 2013, but it was not clear if that group was connected to the incident.
