CAIRO: A suicide bomber detonated a car packed with explosives at a police compound in Egypt's Nile Delta on Tuesday, killing 15 people, the interior ministry said, in one of the deadliest attacks since the army deposed President Mohamed Mursi in July.
At least 12 policemen were among those killed in the overnight blast in the city of Mansoura, north of Cairo, and about 140 people were wounded, 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.
"We heard a loud noise and I found blood all over my body," one wounded man told state television, speaking from a hospital bed with his head wrapped in bandages. "We all ran downstairs to find our colleagues on the ground in blood."
The attack prompted a cabinet statement declaring Mursi's Muslim Brotherhood a terrorist organization, though officials did not directly accuse the group of staging the attack.
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 interior ministry said the car bomb attack was carried out by a suicide bomber, citing evidence gathered at the scene.
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.
The security forces have killed hundreds of his supporters as part of a campaign to repress his Muslim Brotherhood, until then Egypt's most powerful political and religious organization, while lethal attacks on the security forces have proliferated.
Some analysts say Egypt could face a sustained Islamist insurrection, a risk compounded by a flood of weapons smuggled out of neighboring Libya since the uprising against Muammar Gaddafi began there almost three years ago.