The fire burned all night long. It was only after desperate town residents borrowed the keys to a firetruck that they were able to quell the blaze. By then, the evangelical church was all but destroyed.

It was one of more than 60 churches that have been attacked, vandalized and in many cases set aflame across Egypt in a surge of violence against Christians that has followed the bloody Aug. 14 raid by Egyptian security forces on two Islamist protest camps in Cairo.

The attacks, most of them in Egypt’s Nile Valley, have lent legitimacy to the military-backed government’s claims that it is fighting a war against terrorism.

But one week after the attacks, the Egyptian government has yet to investigate any of the incidents or provide any additional security to most churches, Christian activists and church officials said.

Visits to flame-ravaged churches and interviews with activists and Western officials also cast doubt on whether the Muslim Brotherhood, blamed by the government for carrying out the violence, was actively involved.

“We have seen zero indication that the Muslim Brotherhood as an organization is organizing these attacks,” said a high-ranking Western official who was not authorized to speak on the record. The official said the blame more likely rested with Islamist vigilantes rather than Brotherhood members acting on orders.

Adversaries and abettors

In places such as Beni Mazar — a town on the Nile about 160 miles south of Cairo in Minya province, which is riven by sectarian tensions — Christian residents made clear their sense of fear and anger. They said they believed Islamists had attacked the churches in retaliation for the police raids on Islamist protest camps in Cairo and also to punish Egypt’s Christian minority for its support of the July 3 coup that ousted President Mohamed Morsi. On the day of the raids, Islamists also attacked police stations across the country.

But in interviews Monday and Tuesday, many residents suggested the police had been complicit, at least through a failure to respond.

“Until now, we have not heard about any real or serious investigation,” said Mina Thabet, an activist with the Maspero Youth Union, a Christian activist group, which has charted the attacks that have taken place nationwide since Aug. 14.

Some “five or six” bearded Islamists with assault rifles broke through the evangelical church gate in Beni Mazar around midday Aug. 14, the owner of a Christian bookstore next door said in an interview this week. But he also said those Islamists worked in coordination with dozens of “thugs” who arrived in pickup trucks and didn’t look like Islamists.

The accomplices carried off thousands of dollars’ worth of computer, video and audio equipment, as well as air-conditioning units, before setting the church on fire, according to the owner, who for security reasons would permit the use of only his first name, Ayman.

Later, in the same neighborhood, plainclothes police officers armed with assault rifles came running up to two Washington Post reporters as they moved to inspect the damage at a Christian charity that had been torched next to the police station. The station’s police chief, who gave his name as Gen. Samir, pointed out that his forces had also come under attack in the violence of Aug. 14, and he provided a thick stack of pictures to document one such assault, on a local headquarters for the traffic police.

But Samir said his men had not visited the three churches and other Christian properties that were attacked within blocks of their headquarters. “To do what?” the police chief said, adding that an investigation was the district prosecutor’s job.

The evidence of anti-Christian attacks remained fully on display across Minya, in places such as a Jesuit school in the provincial capital, also called Minya, where vandals had scrawled “Egypt is Islamic’’ on the gate. The Mar Mina church, near a Brotherhood rallying point, had also been emblazoned with the word “Islamic.’’

Some witnesses said attackers had chanted against military rule, and one man said the group he saw attack a church had worn green headbands marked by the Muslim Brotherhood’s crossed-swords insignia.

Ahmed al-Behairy, a Muslim Brotherhood official in Minya who is now on the run from police, said in a telephone conversation that “families” in the province had opened fire on police targets last week in retaliation for the deaths of peaceful Islamist protesters. “Those who know the nature of the Upper Egyptian people know that they believe in revenge,” he said.

But Behairy said it was “absolutely not true” that protesters had attacked churches, and he blamed those assaults on thugs determined to “cause problems.’’

A history of conflict

Egypt is overwhelmingly an Islamic country, and Christians make up only about 10 percent of the national population. But in the conservative Nile Valley, in cities such as Beni Mazar and Minya, Christians account for a far larger percentage of the population. For decades, sectarian rivalries between Muslims and Christians have frequently spilled over into violent clashes — a phenomenon exacerbated by the 2011 uprising that brought Islamist groups to power as nationwide security collapsed.

Egypt’s security forces have rarely stood in the way of the country’s explosive sectarian violence, and the senior Western official said it was not out of the question that the security forces — who typically do not wear uniforms and sometimes carry weapons concealed in their long, flowing galabiyas — had played a role in stirring last week’s violence.

Some residents interviewed in Minya province said they believed the Brotherhood has blamed Christians because of the support voiced by Pope Tawadros II, the Coptic Church leader, for the July 3 military takeover that ousted Morsi.

Among the attacks in the provincial capital was one that led to the burning of the 95-year-old Amir Tadros church, several blocks from the governor’s office.

Those present at the time included Michael Kastour, a church member, who said men armed with machetes had hurled stones and molotov cocktails over the wall before forcing their way through the metal gate.

Kastour fled up a staircase to the church’s roof, he said, and then leapt to a lower stone dome and onto the street. He said that he and his father, a church official, called the military and police several times while the church was being looted and then set ablaze, but that neither had proved willing to respond.

“We believe the military didn’t interfere that first day so that the Muslim Brotherhood could show all their cards and appear before the world as they truly are — terrorists,” Kastour said. “Normally it takes time” for the police to respond to reports of sectarian violence, he said. “But that day, they refused entirely.”

Sharaf al-Hourani in Minya contributed to this report.