By Alix Kroeger
BBC News, Baghlan, Afghanistan
The lane leading to the Baghlan sugar factory is lined with trees. All of them have been painted white at the base, but one is now blackened.
The attack was called the worst in Afghanistan since 2001
This is where a suicide bomber detonated explosives last week.
In all, around 70 people died here. More than 100 people were injured.
The bomb, laced with ball bearings, targeted a delegation of MPs, but most of the victims were schoolboys, there to welcome the visiting dignitaries.
In the confusion after the blast, bodyguards working for the MPs opened fire.
When we arrived in Baghlan, north of Kabul, survivors and the bereaved clustered round us in minutes, eager to tell their stories.
Most of the injured were schoolboys gathering to greet the MPs
Mahmad Jaweid, 15, was on crutches. He was one of the walking wounded - one of the lucky ones.
He had been brought by his teacher to welcome the MPs. He ran away when he heard gunfire but was injured in the leg.
Shafiqullah, 18, lost two of his brothers in the blast. One of them was 10, the other 11.
'Enemies of Afghanistan'
After 30 years of conflict, Afghans have had to get used to violence. But this bombing shocked the country profoundly.
Partly because of the high number of deaths, partly because so many of the dead were children. And partly because no-one has claimed responsibility.
Many people blame what they call "the enemies of Afghanistan" - a phrase that can cover the Taleban, other insurgents or the factions led by various warlords.
But they also blame the government, for failing to protect them and their children.
Waladaji Barakat, a farmer, lost one of his sons and another was injured.
He said he would continue to send his sons to school once the period of mourning was over and the school had reopened. But one of his neighbours said he was withdrawing his children.
And all of them agreed, they would never send their children to greet visiting officials again. They did not trust the government to protect their children from attacks.
But whether the school will be able to reopen is unclear.
Five of its teachers were among the dead.
Since 2001 and the fall of the Taleban, the number of schools in Afghanistan has skyrocketed. In a small town like Baghlan, finding so many qualified teachers will not be easy.
For Mohammad Fahim, one of the teachers who was unharmed, the suicide bomb meant the loss of five of his colleagues. One of them was also his father.
Ribbons mark the place where the bomb exploded
"Representatives of the government should not use bodyguards who have no experience and no judgement. When the bomb went off, the bodyguards opened fire and killed some of our young people."
He pointed out two school exercise books belonging to a 16-year-old pupil, still lying on a dusty wall opposite the spot where the bomb went off.
He would never claim them now.
Ribbons in the colours of the Afghan flag - red, green, black and white - were tied round a nearby tree. No other visible marks remained.
Rumours that it might have been a roadside bomb, a landmine or a rocket attack circulated in the immediate aftermath of the explosion.
But there were no marks on the pavement. And all the eyewitnesses we spoke to confirmed it was a suicide bomb.
Dr Ahmad Zia Muzhda, who treated some of the wounded, was certain of one thing - the bomber did not come from Baghlan.
"Nobody wants to kill their own sons or the sons of this province," he declared. "No-one would want to destroy his home by his own hand."
Victim Mustafa Kazimi was a prominent opposition figure
But the truth is that nobody really knows. The Taleban have denied responsibility. So have the Hezb-e Islami faction led by Gulbuddin Hekmatyar, which has a strong base in Baghlan province.
As well as the government in Kabul, anger has been directed at the provincial governor and the police commander.
Neither was in Baghlan at the time of the attack.
The governor of Baghlan refused to speak to us. The police commander, Maulana Abdurrahman, defended his absence, saying he was at a seminar in Mazar-e-Sharif.
He was among those who blamed the "enemies of Afghanistan".
"If they attacked the army or the politicians, we'd say these are enemies of the government," he argued.
"But by attacking the students, they attacked all the Afghan people."
Outside the commander's office, a man with a video camera showed us some footage. He was a police officer who had been filming the MPs' arrival.
The pictures showed Mustafa Kazimi, the most prominent of the MPs striding along the lane and being handed a bunch of flowers by a pupil.
Unclaimed belongings will be buried under a white flag
Then there was an explosion. A couple of minutes later, the tape showed a man holding up what he said was the head of the suicide bomber.
Cmdr Abdurrahman did not want to say whether he thought there would be more suicide attacks in Baghlan.
"Do you know of any suicide attacks which have been prevented?" he asked, intending the question to be rhetorical.
In fact, there had been one in the neighbouring province of Kunduz just the day after Baghlan.
A suicide bomber had blown himself up before reaching his intended target when he realised he was being followed by a secret policeman.
The policeman and one other person suffered minor injuries. The only person to die was the bomber.
Milestone of violence
At a building next to the Baghlan sugar factory, a tattered grey mailbag held some of the objects recovered from the scene. There were sandals, a policeman's cap and a Unicef exercise book.
The Unicef logo was almost obscured by the blood that had dried on it.
The man who showed us the bag said they would bury the objects in a special pit. A white flag would be put up to remember the innocence of the victims.
The political shockwaves of the Baghlan blast continue to ripple out.
On Monday, the Afghan parliament said the weakness of the authorities was the main obstacle to improving security in the country.
Since the insurgency began two years ago, suicide bombings have become almost commonplace in Afghanistan.
But Baghlan marks a new milestone of violence. One many Afghans wish had never been reached.