For the teachers and health workers serving the village of Sher Afzal Banda, there were few things more mundane than their daily return journey to work.

Every morning a cramped Suzuki minibus owned by the charity Support With Working Solutions (SWWS) would collect them from the junction on a main road and drive them down the rough country track, just wide enough for a single vehicle. In the late afternoon it would bring them back.

"She never thought she was running a risk," said Zain ul-Hadi, the husband of Naila, a 28-year-old who led a team providing basic healthcare to some of the 2,000 people who live in traditional mud houses in the village in Pakistan's Khyber Pakhtunkhwa province. "She had no reason to be scared of anyone."

He last spoke to her on Tuesday afternoon, when she called to confirm she would meet him as normal. "She said she was on her way and I said I would be waiting to pick her up." Thirty minutes later she and six out of the nine people, mostly fully veiled women, riding in the Suzuki would be dead, murdered by as yet unidentified militants while they sat inside the vehicle.

The appalling incident has raised fresh alarm about the growing willingness of Pakistan's increasingly brutal militants to attack civilians. Like many other parts of the country where ethnic Pashtuns live, the district of Swabi has had its share of trouble with militancy. But while some schools have been blown up, no one can recall anything like last week's attack.

One victim, a male nurse called Umjad Ali, had even moved home from his employment in Karachi after his family feared for his safety in the strife-torn coastal megalopolis.

The two gunmen, faces covered with cloth, had picked their site carefully. Their motorbikes were parked at a narrow point where the road dips, forcing traffic to slow down. There were no people or houses for miles around, only fields sown with a young wheat crop.

The driver, who survived a bullet in his chest, asked whether he should try to smash past the two sinister, pistol-brandishing men. But Umjad Ali thought it better to stop and talk.

In one apparent act of mercy, one of the men pulled Naila's four-year-old son, Ehsan Shehzad, out of the vehicle and threw him into a field after she begged that he be spared. The gunmen asked for everyone's mobile phones, but then began shooting through the windows of the vehicle before the devices were handed over.

In a part of the world where people hate to break the worst possible news over the phone, relatives of the six women and one man eventually received calls saying their wives and daughters were "seriously hurt" and they should come immediately. Days on, they are all still in deep shock.

"When the Taliban killed the polio vaccination team it occurred to me she could be targeted as well," said Umara Khan, father of Shourat, a 28-year-old who taught in Sher Afzal Banda's small primary school. "But I did not ask her to leave, she loved to teach."

Like many of the other families affected, Shourat, with her well-paid NGO job, was the main breadwinner for her household.

"What are they trying to achieve? I don't know," said Hussain Wali, the father of Rahilla, a 25-year-old teacher who was also in the Suzuki. "We did not have a sense that women, teachers and health workers would be targeted."

On Friday police claimed that one of the culprits blew himself up after the police attempted to arrest him.

The incident in Swabi comes after the killing of nine people working on UN-backed anti-polio vaccination teams during a string of attacks last month.

In October, Malala Yousafzai, a schoolgirl from the nearby district of Swat, survived being shot in the head by a Taliban gunman, who objected to her fight for girls to be educated. Last week she was discharged from hospital in Birmingham after weeks of treatment. In December, militants kidnapped 23 tribal police. Observers say that in the past the militants would probably have tried to trade them for a ransom, but 21 of them were killed with no demands made.

"Things are changing, things have been happening that never happened in the past," said Rahimullah Yousafzai, a journalist based in Peshawar who has been covering the tribal area for decades. "Attacking mosques, funerals, graves and, of course, these teachers and health workers."

Yousafzai says Pakistan's militants have come to see anyone involved in charitable or development organisations as fair game: "They take it for granted that if you work for an NGO you are funded by the west, that you are trying to change local traditions and customs, you are doing something that is secular. They no longer expect to get any public support, so no effort is being made to win hearts and minds. That is beyond them. Now all they want is to intimidate and pre-empt an uprising against them."

For the time being, the people of Sher Afzal Banda are defiant. Local residents say they want the school to be reopened as soon as possible.

Javed Akhtar, executive director of SWWS, is considering hiring armed guards for his staff. Like most humanitarian workers, he hates the idea of using guns but sees no alternative. But he fears more trouble. As in nearby Swat, the people of Swabi have a strong commitment to educating their daughters and the district boasts a high female literacy rate. "Malala survived, she was discharged from hospital – that is a big defeat for them," he said. "They now want revenge, they want to kill many Malalas."