CAIRO (AP) -- A series of three bombs went off Wednesday outside Cairo University, killing a police general and wounding seven people, introducing a new level of violence to the almost daily battles at campuses fought by Egyptian police and students loyal to the ousted Islamist President Mohammed Morsi.
Universities have emerged as the main center of the campaign of protests by Morsi's supporters against the military-backed government that replaced him, because a fierce crackdown the past nine months has made significant rallies by Islamists in the streets nearly impossible.
The result has been increasingly deadly clashes between protesters and security forces in and around the walled campuses, with several students killed the past weeks.
Wednesday's blasts targeted a post of riot police deployed outside Cairo University in case of protests, in apparent retaliation for police assaults. That would be a significant escalation and raises the likelihood of a fierce response by security forces that would further push a spiral of violence at the universities.
A new group that first appeared in January, Ajnad Misr, or "Egypt's Soldiers," claimed responsibility for the bombing. In a statement, it said it was waging a campaign of retribution and that the slain police general had been involved in killings of protesters. It said the attack also came in response to increased detentions of female protesters.
The main pro-Morsi university group, "Students against the Coup," led by Morsi's Muslim Brotherhood, denied involvement in the bombings.
But a leading figure in the group, Youssef Salheen, warned that excessive violence by the security forces and the broader crackdown on the Brotherhood was fueling a violent response.
"All that is incitement to all those who go down to protest to turn from peacefulness to violence and terrorism because of all what they see," said the 21-year-old Salheen, a student at Cairo's Islamic Al-Azhar University, another campus that sees frequent clashes. He said his group is working against the radicalization of protesters.
Since the military removed Morsi in July, the interim government has been waging a fierce crackdown on the Brotherhood and other Islamists, killing hundreds and arresting more than 16,000.
At the same time, police and the military have faced a campaign of car bombs and suicide bombings hitting security facilities and assassinations of officers. In some cases, security officers' cars have been torched.
Many of the biggest and most sophisticated attacks have been claimed by an al-Qaida-inspired militant group based in the Sinai Peninsula. Ajnad Misr has claimed several smaller bombings since January. The government accuses the Brotherhood of orchestrating the violence, branding it a terrorist organization -- a claim the group denies and calls a pretext for wiping it out.
Wednesday's blasts -- using what authorities said were crude homemade explosives -- were rare in that they targeted police forces in the field directly deployed to face protesters.
The three blasts were also staggered in time. The first two bombs, which security officials said were hidden at the foot of a tree, went off less than a minute apart near a security post of riot police, security officials said.
The third, concealed up another tree nearby, exploded nearly two hours later, the officials said, speaking on condition of anonymity because they were not authorized to talk to the press.
Ajnad Misr said in its statement that the third blast was delayed to spare civilians nearby. The tactic has been frequently used in Iraq by Sunni militants fighting the Shiite-led government -- using secondary explosions to target members of the emergency services and reinforcements who come to the aid of those wounded in the first blast.
The first two blasts sprayed nails packed into the explosives, killing police Brig. Gen. Tareq al-Mergawy, with a nail that pierced his heart, a spokesman for the state forensics department, Hesham Abdel-Hamid, told the private TV CBC.
Four civilians and three senior police officers were wounded, including the deputy police chief of Giza province, where Cairo University is located.
After the bombing, police chased down and detained several students on the streets nearby, but there was no immediate word on the number of arrests made.
The country's most powerful political figure, former military chief Abdel-Fattah el-Sissi -- who removed Morsi and this month left the military to launch a run for president -- denounced the bombings in a statement issued by his election campaign.
"Egypt will march forward and will not succumb to black terrorism," he vowed.
After an emergency meeting of top security and intelligence officials, the government announced it would deploy more forces outside universities and will expedite the issuing of a new anti-terrorism law. The new law reportedly expands the definition of terrorism, allows for greater Internet surveillance and creates a special prosecutors' office for terrorism crimes with expanded powers.