Egyptian forces defused a bomb placed in a car and primed to explode on a roadside near the capital Cairo on Monday, security officials told AFP.
The interior ministry said the stolen car was detected near a petrol station on the road to the city of Suez.
An employee at the petrol station, which local residents said belongs to the army, spotted three people parking the car and leaving on foot, one official said.
Security officials said the apparent target was a passing convoy.
Egypt has seen a surge in violence and terrorism since July 3, when the military ousted Islamist President Mohammed Morsi, a member of the Muslim Brotherhood.
In addition to protests and clashes that have left scores dead since Morsi’s ouster, police and soldiers have become prime targets of terrorists, particularly in the lawless Sinai Peninsula.
The Egyptian armed forces have launched large scale military operations against terrorists in Sinai in an attempt to suppress the insurgency.
In response, a torrent of attacks by gangs of Al Qaeda-inspired Islamic terrorists have killed over 100 Egyptian soldiers and policemen since Morsi's overthrow.
On September 5, Egypt’s interior minister Mohamed Ibrahim escaped unhurt from a roadside bombing.
The government has arrested 27 people suspected of involvement in Ibrahim’s assassination attempt, all members of the Salafist Ansar Beit al-Maqdis terror group.