Gunmen shot dead a military officer and injured three soldiers near Al Zaytoun hospital in east Cairo early Thursday morning, Al-Ahram Arabic news website reported.
Two assailants  on a motorcycle attacked an armed forces' bus transporting the soldiers.
Witnesses and local residents said they heard gunfire but could not specify where it came from.
There has been a surge of attacks on police and army targets since the ouster of president Mohamed Morsi in July 2013. In North Sinai, more than 175 members of the security forces have been killed in attacks by militants. 
Attacks on security personnel  have taken place in the Upper Egyptian city of Beni Suef, Al Badrasheen in Giza, the southern city of Aswan, the Nile Delta city of Mansoura, Sharqiya and a number of others.
Interior Minister Mohamed Ibrahim  survived an assassination attempt in Cairo last September.