A bomb exploded near a Cairo bus on Thursday morning, injuring five people. No deaths were reported in the blast, which comes just two days after a huge explosion outside a police building in the northern city of Mansoura killed 16 people.
The explosion on Thursday took place on Mostafa Nahas Street in Nasr City, an affluent suburb of eastern Cairo. The street is close to an Al-Azhar University building, the headquarters of the National Security apparatus, and a police station.
According to investigating prosecutors and eyewitnesses, the bus had broken down, causing many passengers to disembark and seek alternative transport just minutes before the bomb detonated.
Investigations also revealed a half metre wide hole in the ground underneath the bus from the impact of the explosion.
The area was immediately cordoned off by the police for investigations.
The wounded were transported to the Health Insurance Hospital in Nasr City, Head of Ambulance Service Ahmed El-Ansary told Al-Ahram Arabic website.
The director of the explosives department at the Ministry of Interior Alaa Abd El-Zaher told Al-Ahram Arabic that his experts also found an undetonated bomb planted in an advertisement stand in the garden in front of the school complex.
Explosives experts confirmed upon examination of the bomb that it was home-made and contained gunpowder, nails and broken marble, Abd El-Zaher said.
Meanwhile, a number of eyewitnesses told Al-Ahram that the bomb exploded inside the bus and was not thrown at it as some officials seemed to indicate earlier.
An eyewitness stated that the public transportation bus, number 969, carried few passengers at the time of the bombing.
She added that the explosion occurred at 9:15am (CLT) and that passersby and police rushed to the bus to extricate the wounded.
The explosion did not affect surrounding vehicles and stores, the eyewitness added.
New explosion in tense weeks
The bombings come one day after Egyptian interim government declared on Wednesday the Muslim Brotherhood, from which ousted president Mohamed Morsi hails, a terrorist group.
The interim government reached its decision against the Brotherhood one day after a deadly explosion rocked the Daqahliya Security Directorate in the Nile Delta city of Mansoura. The bombing, which took place on Tuesday morning, resulted in the death of 16, mainly policemen, and the injury of more than 135.
The Muslim Brotherhood denied on Tuesday involvement in attacks on government buildings and security personnel.
Ansar Bayt Al-Maqdis, an Al-Qaeda-inspired Islamist militant group, claimed responsibility for the Mansoura blast.
Egyptian police announced that no suspects have been arrested yet.
Large protests over the past few weeks by pro-ousted president Mohamed Morsi students at Al-Azhar University, which is located near the site of Thursday's explosions, clashed repeatedly with security forces.
Pro-Morsi students denounced what they described as a "military coup" by the interim government and demanded the reinstatement of Morsi.
They were accused of storming the university's main administrative building in mid-November.
Police responded to student protests with teargas arresting tens.
A pro-Morsi Al-Azhar student was also shot dead during clashes with security forces.
Earlier in November, 12 Al-Azhar University students were sentenced to 17 years in prison over riots at Al-Azhar institution headquarters.
They were found guilty of attempting to storm the headquarters of the institution, which oversees the university, inciting riots and attacking employees and security personnel, as well as destroying public and private property.