Cairo: In one of the deadliest attacks since the Egyptian army deposed Mohamed Mursi from the presidency in July, a car bomb tore through a building in the northern city of Mansoura, killing 15 and injuring at least 140 people.
The blast was so powerful it reportedly shattered windows in buildings kilometres away, ripping apart the five-story building that housed the Daqahliya security directorate.
The attack sparked fears that deadly six-month campaign of violence in the North Sinai against police and security forces that has killed at least 200 was spilling over into the Nile Delta, and raised concerns about the environment in which Egypt will conduct a referendum on its new constitution next month.
Following the attack the cabinet released a statement declaring the Muslim Brotherhood a terrorist organisation, although interim Prime Minister Hazem Beblawi stopped short of openly blaming them for the attack.
Not so the cabinet spokesman Sherif Shawki, who was quoted by the Middle East News Agency as saying the Brotherhood had shown its "ugly face as a terrorist organisation shedding blood and messing with Egypt’s security",
The Brotherhood condemned the bombing, releasing a statement on Tuesday saying it “considers this act as a direct attack on the unity of the Egyptian people.”
No one had claimed responsibility for the Mansoura bombing by Tuesday night, although it came a day after an al-Qaeda-linked group believed to be based in the Sinai called on police and army personnel to desert or face death.
In November a car bomb killed 10 soldiers in the Sinai, and 24 policemen died in an August ambush, meanwhile, there has been an ongoing Egyptian army operation in the Sinai in order, it says, to rein in the militants.
Speaking at a public forum on Monday, Egypt's military spokesman Ahmed Mohammed Ali said the army crackdown has killed 184 militants and arrested 803 others.
But as human rights groups and most journalists have been denied access to the area, the details are impossible to confirm.
As darkness fell on Tuesday local media reported that crowds of people had stormed Mansoura – about 110 kilometres north of Cairo – torching buildings and shops they believed to be owned by Muslim Brotherhood.
Human rights groups fear that the bombing will lead to a further tightening of security and more abuses of power, as the mass arrests of Muslim Brotherhood members widens to include activists prominent in the January 25 revolution that overthrew the former leader Hosni Mubarak.
The bomb blast and its aftermath would create an atmosphere in which the referendum will take place as “anything but free and fair”, said Tamara Alrifai, a spokeswoman for Human Rights Watch in Egypt.
The interim government had already begun a campaign to encourage Egyptians to vote ‘yes’ in the January 14 referendum.
“Increased security, increased intimidation, but also increased attacks if they happen, will not make it easy for those who want to vote ‘no’ to go and vote ‘no’,” Ms Alrifai told Fairfax Media.
“Even before what happened today we had a concern about [whether] people could really express their opposition to the referendum.”
Last week prosecutors ordered Mursi and other Brotherhood leaders to stand trial on charges including working with foreign militants to carry out terrorist attacks in Egypt – charges the Brotherhood denies.