Image caption Rukhsana Bibi eloped with Mohammad Yunus last May

On a hot and humid night in late August, a small group quietly scales the wall of a mud-brick house in a village near Pakistan's north-western town of Akora Khatak.

In the dim, starlit courtyard, they make out the figures of a man and a woman lying in two separate charpoy cots, sleeping. About 15 minutes later, they walk out through the main door, leaving the couple in pools of blood.

This description of the scene in Akora Khatak forms the backdrop to allegations of a so-called "honour killing", one of the great unspoken stories of the Pakistan-Afghanistan region where it widely prevails. Nowhere is it pursued as doggedly as in Kohistan, a remote and mountainous region in northern Pakistan.

Image copyright bbc

The code is simple: Any contact, even just communication between a man and a woman outside of customary wedlock is considered a breach of the honour of the woman's family, and gives it the right to seek bloody revenge.

The woman's family must first kill her and then go after the man.

The mere expression of suspicion by the woman's family is enough evidence and the community demands no further proof.

Once such a suspicion has been expressed, local custom prevents the family of the man killed in this way from avenging his death or reporting it to the police.

By their very nature, "honour killings" are particularly difficult to prove or to prosecute. There are frequently no witnesses to the crime and little motivation for the police to pursue any suspects, irrespective of the evidence.

One person who hopes to change that is Rukhsana Bibi, now a widow, who claims that she survived an "honour killing" in a village near Akora Khatak and has taken the unusual step of publicly speaking out, trying to seek justice through the legal system.

Ms Bibi suffered horrific chest and leg injuries when she and husband, Mohammad Yunus, were victims of a brutal attack while they lay sleeping in the courtyard in Akora Khatak. Her husband was murdered, but Ms Bibi survived with seven bullets in her body: two in the chest, three in the left leg and two in the left hip.

She still suffers bouts of weakness because of her injuries. She was so badly hurt that she needs a walking frame to move around.

Image caption Rukhsana was so badly hurt in the attack that she needs a walking frame to move around

Ms Bibi was 18, and her lover, Mohammad Yunus, 22 when they decided to elope on 22 May last year. "I had no choice," she explains to me as we sit in a small, cramped room somewhere in northern Pakistan where she is hiding. "I either had to kill myself, or run away."

Ms Bibi tells me that she met Mr Yunus - a student of medical technology - at a village wedding in the summer of 2011. They fell in love with each other at first sight.

Although their meetings were rare, they frequently spoke to each other on their mobile phones.

She describes how their relationship went on like this until April, when her family arranged her marriage to a distant relative, an uneducated cattle tender in her village.

Unhappy and frustrated, she and Mr Yunus decided to run away.

They married in the north-west before going into hiding in the Akora Khatak area.

But Ms Bibi now strongly believes that the brutal attack which killed her husband in August was undertaken by various relatives seeking to avenge the disgrace which they believe she had brought upon her family honour.

She has given her account of the evening when she was attacked to the BBC.

Media playback is unsupported on your device Media caption A group of women were reported to have been killed in Kohistan in 2012 after footage showed them singing and dancing, as Orla Guerin reported

"I must have heard the footsteps in my sleep," she says, recalling the incident.

Tears roll down her cheeks as she narrates her story, but her face is expressionless, and her voice does not tremble.

"I opened my eyes.

"All of them were armed. I knew our end had come, so I shouted to my sleeping husband."

The intruders shot her first, apparently in compliance with the custom, and then turned on her husband, pulling him off the bed and pumping bullets into his body.

"They continued to fire shots at us for a long time. Sparks flew in our house like the flashes from a big explosion. I was screaming at first, but then I pretended I was dead."

I am a dead person anyway, but I have to get justice for myself and my husband Rukhsana Bibi

Regaining consciousness after the attack, Ms Bibi discovered that she had fallen over and that her left leg was lying limply on the ground.

"It felt so heavy, I couldn't lift it to the bed," she says, her voice steady.

She witnessed her husband dying in a pool of blood on the ground next to her.

She thought she saw him breathe.

"He was alive for a minute or two after they left. I couldn't move, so I called his name. He turned his eyes to look at me for a brief moment. Then his head sank to the ground."

Neighbours who heard the firing and her screams arrived at the scene some 15 minutes later and took her to hospital. Unquestionably they saved her life.

Her determination to stay alive has meant that she was able to identify those who she claimed had carried out the attack. Police have issued arrest warrants for some of those who Ms Bibi has claimed were amongst her attackers.

Whether this was actually an "honour killing" as Ms Bibi claims, and whether any case can be proven in court remains uncertain.

One of those she has named as a suspected attacker has a strong alibi. When contacted by the BBC, he denied that he was one of Ms Bibi's relatives or had any involvement in the attack, stressing that his colleagues had vouched for him on the evening of the attack when he was working many miles away. He also claimed that another of the accused had been falsely implicated by Ms Bibi.

He alleged that Ms Bibi had done so in order to protect herself against those who had sought to kill her and husband. Another of the suspects also denied any involvement in the murder. He claimed that the allegations were a "misunderstanding" and alleged that as Mr Yunus had previously been involved in an unrelated murder allegation, the attack on him and Ms Bibi was likely to be the result of somebody "avenging" a previous incident.

Whether Ms Bibi's case will ever come to court is therefore unclear. Her allegations are unproven, and although arrest warrants have been issued for some of those suspects who she has identified to police, any actual arrests and interviews by the police are not thought to be imminent.

These interviews are necessary before a police investigation can determine whether there is sufficient evidence behind Ms Bibi's allegations to charge any suspects. Until then, the motive for the attack on her and the actual identity of her attackers remains undetermined.

"Fighting such a case in the court is tough, but when I go for hearings, I don't feel any pain in my body," she says.

"I am a dead person anyway, but I have to get justice for myself and my husband. We did no wrong."

For centuries, Kohistan's "honour" killings have remained as little reported as the region itself.

But in recent years there has been greater scrutiny, and deaths have been more frequently reported to the police.

One reason appears to be the growth of mobile telephone technology, which has sparked differences over what constitutes an "honour" killing.

The first big challenge to this unwritten code came in May 2012 when someone in the area circulated a mobile phone video showing some women and men dancing and clapping at a wedding.

It is alleged that some men from the families of the women decided they had been shamed and reportedly killed four women shown in the video, as well as a fifth girl for acting as a messenger. They are also accused of killing three brothers from the men's family.

But a dispute apparently arose when the family of the brothers complained that relatives of the women had the right only to kill the two men who had appeared in the video.

The women's family are said to have argued that since they had killed five of their women, the custom also allowed them to kill five men.

The case was picked up by the Supreme Court and human rights groups, but it was left unresolved due to local complications.

However, the publicity it attracted probably did save some lives and encourage other affected families to report such killings to the police.

Since April, police in Kohistan have registered at least seven reports in which 10 people have been killed, allegedly for "honour", seven of them women.

While these figures suggest that the police have become more active in registering complaints, few people named in them have actually been arrested. That may be because many of those accused wield considerable influence.

There are then the difficulties of the terrain to contend with.

Image caption Police in Kohistan are trying to be more active in tackling honour crime

"Each police station covers a 70- to 80-square kilometre area, all of it mountains and deep valleys that take a police team days to reach," says Ali Akbar, Kohistan's district police chief.

"Hours before the police can reach a village, the villagers have advance information of their arrival and send the wanted men into forests and caves to hide."

Furthermore, there appears to be an enigmatic bond between the prospective killers and their likely victims which the police have no clue how to break.

There is considerable evidence that women declared tainted by their families have chosen to die rather than seek outside help, even when this is easily available.

But for Rukhsana Bibi, the mere fact that more people are willing to consider reporting "honour"-related killings to the police is a sign of change.

"I am not alone," she says. "All girls are treated like this in Kohistan, and since most of them are uneducated, they can't fight.

"But the new generation is changing, God willing. They just need a little help from the courts and the government."