Security forces rushed to the place of the bomb and are currently investigating the incident.
Primary investigations showed that the bomb took place in a private car in Abu Kabir area in Sharqiya and the three persons were inside the car when exploded.
Militant attacks targeting police and military increased after the ouster of Islamist ex-president Mohamed Morsi in 2013, who ruled for nearly three decades, by military following massive protests against his rule.
Over 600 security personnel have been reported killed since then.