By Tom Perry and Alexander Dziadosz
CAIRO/MINYA PROVINCE (Reuters) - Gunmen who fired rocket-propelled grenades at a police station near Cairo and slit an officer's throat daubed the wall with a warning before they left: "This is the penalty for the oppressors."
The masked assailants attacked a few hours after the security forces began breaking up protest camps set up by supporters of deposed President Mohamed Mursi in an operation last Wednesday that killed hundreds of people.
The surge in violence has raised fears that a new Islamist insurgency may take root on the Nile, where militants waged a failed campaign against the state in the 1990s.
"Have you ever seen war on TV? That's what it was like," said one passerby, speaking in hushed tones outside the abandoned police station in Kerdasa, its scorched facade riddled with bullet holes. He declined to give his name.
The government said nine policemen were killed in the assault in Kerdasa, a bastion of Islamist support.
Residents described offering shelter to terrified policemen who fled the building, aiding their escape by giving them civilian clothes to change into.
Outside stood the charred remains of 13 vehicles, two of them armored personnel carriers. Not a policeman was in sight.
Two dozen police stations were attacked across Egypt that day, perhaps heralding more unrest that could cripple hopes of democracy kindled by the 2011 overthrow of Hosni Mubarak.
No group has claimed responsibility for the attacks, of which two involved rocket-propelled grenades and all, gunfire.
To the east, the Sinai Peninsula is already in the throes of an insurgency by hardline Islamists - at least two dozen policemen were killed there in an ambush on Monday.
A spate of attacks in the Nile Valley and cities along the Suez Canal since the army toppled Mursi on July 3 points to the risk of militancy spreading to the more densely populated areas of the country of 85 million.
Some towns in Minya, a province south of Cairo, already resemble war zones, with police stations, churches and other targets hit in persistent violence since Wednesday.
Militants have also struck in three cities along the Suez Canal, a vital world shipping artery, killing at least seven policemen. Shipping has not been affected. Security forces are heavily deployed. Soldiers are even guarding petrol stations.
Weapons, mostly smuggled from Libya, are more freely available than in the past.
With the Internet helping al Qaeda's ideas to spread more easily than in the past, the movement now led by an Egyptian, Ayman al-Zawahri, will likely find new adherents on the Nile.
The decades-old struggle between the army-led state and Islamists may be about to enter a bloody phase with a new cast. "Now is a very good time for al Qaeda to recruit," said Khalil al-Anani of the Washington-based Middle East Institute.
The government accuses the Muslim Brotherhood of terrorism, saying its protest camps represented a threat to national security. Its leaders face trial for inciting violence.
The Brotherhood, its strategy long built around peaceful political and social activism, denies those charges. Some Islamists say the state is trying to provoke violence - something they say happened in the 1990s.
The Brotherhood, pointing to the repeated mass killings of its followers since early July, says the government's charges of terrorism are intended to justify an even tougher crackdown.
But while the Islamist group repeats its mantra of peaceful resistance, it has spoken of uncontrollable anger in the street. Gunmen have appeared at some pro-Mursi protests in Cairo.
With the Brotherhood's organizational structure under heavy strain, the risk of splinter groups emerging has risen.
"Egypt is fertile. It isn't just the Islamic Jihad or other organizations. These are over, finished. But if one dies then another will come along," said Yasser el-Sirri, an Islamist who was sentenced to death in Egypt in the 1990s. He was speaking by telephone from Britain, where he has asylum.
Online, hardliners have called for an armed response, calling for a "military jihadi current", according to SITE Intelligence Group, which monitors radical websites.
The past week's violence, in which officials say nearly 900 people have died, including almost 100 soldiers and police, has dwarfed the rate of killing in the 1990s.
On Wednesday alone, 70 people, 16 of them policemen, were killed in Minya province.
In the Minya town of Mallawi, churches have been torched, along with Christian homes and shops. People speak of masked men staging repeated attacks on the police station with impunity.
Men in civilian clothes patrol with assault rifles, though it is unclear if they are plainclothes police or belong to the "popular committees" starting to fill a state authority vacuum.
Makeshift barriers of bricks and planks block a road to the police station. An armored Interior Ministry vehicle was parked nearby. Gunfire crackled every few minutes.
Nagi Helmy, a pharmacist, has heard heavy gunfire from both sides since Wednesday. "The shooting has been very violent, both from those attacking and from the police," he said.
Ayub Youssef, a Catholic priest from the nearby town of Delja, described similar scenes there. Islamist protesters torched the local police station on Wednesday after attacking Christian homes, he said.
Many of the hardliners were armed with automatic weapons trafficked across the Saharan desert into the town, he said.
Youssef said the violence was worse than anything he recalled during the insurgency of the 1990s, when militants killed Christians and burned churches in the same area.
NEW FIGHT BREWING?
The Interior Ministry, which was beefed up under ousted President Hosni Mubarak to battle the Islamists of the 1990s, appears to be gearing up for a new fight with an old enemy.
Thirty-five officers who were suspended or reassigned after Mubarak's overthrow have been brought back to the State Security branch since July 3, a security official said.
Hussein Hamouda Mostafa, a former State Security brigadier, sees the scope for an even more ferocious campaign than the one waged in the 1990s by groups including Gamaa Islamiya - a movement once aligned with al Qaeda but which later renounced violence and entered mainstream politics as a Brotherhood ally.
"Now you have 3,000 people in Syria who will come back tomorrow to Egypt. What are they going to do?" asked Mostafa, referring to Egyptian militants he said were fighting the Syrian military.
Echoing the official view, he described the Brotherhood as a "terrorist organization" which views others as infidels.
He also says Western support for the group may encourage violence, mirroring an Egyptian perception, denied by Washington, of U.S. backing for the Islamists.
"It is worse now than in the 1990s," said Mostafa. "They want a civil war. We want to contain the situation," he said.
Others with knowledge of Islamist movements dismiss the idea that the Brotherhood is tempted to espouse armed struggle.
"I am certain that for the Brotherhood, violence is in nowhere on the table. The fear is from some of the members of Gamaa Islamiya that could break away," said Montasser el-Zayat, an Islamist lawyer who defended militants in the past.
He said Gamaa Islamiya leaders had told him they were exerting utmost control over their members, but cautioned: "There are independent elements that embrace extremist ideas, which may - and put a line under that word - be provoked by the security forces."
(Additional reporting by Yousri Mohamed in Ismailia; Writing by Tom Perry; Editing by Alistair Lyon and Philippa Fletcher)