A bomb exploded outside an Egyptian army building north of Cairo Sunday, wounding four soldiers. It was the second bomb attack on security forces in the Nile Delta in less than a week.
The bomb partly destroyed the back wall of the military intelligence building.
The army described the bombing as a " terrorist attack." Its statement referred to "groups of darkness" and did not name the Muslim Brotherhood, the Islamist group it declared a terrorist organization last week.
(SOUNDBITE) (Arabic) HEAD OF SHARKIYA PROVINCE POLICE, SAMEH ILKILANI, SAYING:
''There is no country in the world that can secure itself one hundred percent from terrorist attacks. But here in Egypt we have some of the most competent police officers and armed forces. We work 24 hours a day.''
Tensions are running high in Egypt with student protests at Al-Azhar University going on for a third day in a row.
Students allied to the Brotherhood say they are boycotting exams to protest the killing of classmates by security forces.
The government has declared itself in "a war on terror" as it steers Egypt towards elections. Army chief Abdel Fattah al-Sisi, who led the overthrow of President Mohamed Mursi, is widely expected to win, although he has yet to declare his candidacy.
Blast at Egyptian army building wounds four soldiers (1:28)
Dec. 29 - Four soldiers in Egypt wounded in blast at army building as student protests turn violent. Deborah Lutterbeck reports. ( Transcript )