Why is happening blasts in Egypt?

Car bomb kills 14 at Egyptian police compound

A man walks near a damaged vehicle after an explosion near a security building in Egypt's Nile Delta city of Mansoura in Dakahlyia province, about 120 km (75 miles) northeast of Cairo December 24, 2013. A car bomb tore through a police compound in Egypt's Nile Delta on Tuesday, killing 13 people and wounding more than 130, security officials said.

The army-backed government vowed to fight (black terrorism), saying the attack would not upset a political transition plan whose next step is a January referendum on a new constitution.

The Brotherhood, which is already outlawed, condemned the bombing as "an attack on the unity of the Egyptian people".

Later on Tuesday, hundreds of angry people in Mansoura stormed and torched buildings and shops they suspected to be owned by Brotherhood members, witnesses and state media said.

Others attacked and torched an empty bus after earlier seeing one of its passengers flashing the four finger hand sign symbolizing the killing of hundreds of Mursi supporters at a protest camp broken up by the police in August.

The blast underlined the risk of militancy moving to the densely populated Nile Valley from the Sinai Peninsula, where attacks have killed some 200 soldiers and police since July.

"We face an enemy that has no religion or nation," Interior Minister Mohamed Ibrahim, the survivor of an assassination attempt in Cairo in September, said at the scene of the blast.

The army said a car bomb had been used, while the presidency said such attacks "only increase the state's determination to uproot terrorism". Police "combat units" would deploy across the country with orders to use live ammunition, state TV reported.

Egypt has endured the bloodiest internal strife in its modern history since the army removed Mursi, the nation's first freely elected leader, on July 3 after big protests against him.

Cause of blasts

Al-Ahram’s Arabic website quoted on Tuesday morning an anonymous security source as saying that two bombs had gone off almost simultaneously.

The first bomb, he said, was planted in a higher floor in the building, the second in a car next to the Security Directorate.

A third bomb planted in another car was defused, the source added.

However, Ministry of Interior statements have not specified the sources of the blasts.

A high-profile Ministry of Interior security source told MENA on Tuesday afternoon that primary information indicates a truck containing explosive materials was used in the blast.

The security source said a massive amount of high explosives was used in the incident, pointing out that experts are still examining the site of the blast to determine whether the vehicle had been remotely detonated or exploded through a timer.

Cabinet reactions

Egypt's Prime Minister Hazem El-Beblawi vowed to hunt down the perpetrators of the explosion. He said the attack seeks to obstruct the roadmap drawn up by the country’s interim rulers following Morsi's July ouster by the army amid nationwide mass protests against his rule.

"This is an act of terrorism that aims at frightening the people and obstructing the roadmap. The black hands behind this act want to destroy the future of our country," Beblawi told Egyptian satellite channel ONTV.

"The state will do its utmost to pursue the criminals who executed, planned and supported this attack," he asserted.

Beblawi refused to confirm that Egypt had designated the Muslim Brotherhood a terrorist group, contradicting an earlier statement by one of his aides.

Cabinet Spokesman Sherif Shawqi had earlier blamed the blast on the Muslim Brotherhood group of ousted Islamist president Morsi, and said Prime Minister Hazem El-Beblawi had officially declared the group a terrorist organisation.

“Whoever is behind this act is a terrorist and will be brought to justice and punished according to the law. But I do not wish to anticipate events," Beblawi added.