As Nato quits Afghanistan, new violence threatens the country's presidential election

The Taliban have pledged to disrupt the poll with 'all force'

Poster power: Candidates’ faces line a road in Jalalabad yesterday

When Taliban fighting forced Mohammed Ibrahim and his family to flee their village in Grashak, Helmand, they thought it would be months before they could return. That was five years ago. Now the place that Ibrahim calls home is a flimsy tarpaulin to keep the snow out, strung between three mud walls on the eastern outskirts of Kabul.

Ibrahim, 52, is one of more than 600,000 people scattered from their homes by fighting and insecurity. With a presidential election three weeks away and Nato troops starting to wind down their presence ahead of complete withdrawal at the end of the year, violence in Afghanistan is increasing fast.

Ibrahim is the leader of a camp of 300 families living in Karte Naw, Kabul. He is desperate to return to Helmand but every time he thinks of going back he hears bad news. "Recently we received a report that lots of our relatives have died," he said. "So how can we go back? Two months ago the Taliban came at midnight and killed them using knives. They cut every part of their body. They killed 20 people including three of my extended family.

"Inshallah [God willing] we'd love to go back to our own province. But only if there's security and an opportunity to work." More than 20,000 security incidents were registered by the United Nations last year, making it second only to 2011 in terms of the level of violence seen since the fall of the Taliban. The number of suicide bombings in particular has increased. In the three months to February, there were 35 suicide attacks across the country – more than double the previous year.

At the end of June last year there were an estimated 574,327 Afghanis internally displaced by war, according to the UN. By last month, this had risen to around 630,000. Almost 3,000 civilians were killed in fighting last year, a 14 per cent increase on 2012. The number of these deaths caused by pro-government forces increased by 59 per cent, to 341.

On Monday, the Taliban pledged that they would do all they could to derail the first round of presidential voting on 5 April, warning Afghanis not to take part. "We have given orders to our Mujahideen to use all force at their disposal to disrupt the upcoming sham elections and to target all workers, activists, callers, security apparatus and offices," a spokesman warned.

True to their word, militants kidnapped four election workers in eastern Nangarhar province on Wednesday. On the same day, in northern Faryab province, three elders were shot dead by militants as they left a public ceremony. Then, Taliban fighters armed with hand grenades attacked three campaign offices in Laghman province on Friday. "They killed them to threaten the rest," Mujib Rahman Rahimi, spokesman for the leading presidential candidate, Abdullah Abdullah, told Afghanistan's Tolo News. "They said they would cut off their hands if they voted."

The pattern of election-related intimidation has been going on for months. Vice-presidential candidate and warlord, Ismail Khan was the victim of a failed assassination attempt on 24 January. This was followed by the fatal shooting of two members of Dr Abdullah's campaign team in the western city of Herat on 1 February – and a third in Sari Pul a week later. Dr Abdullah's convoy also came under gunfire when he was returning to Kabul from Nangarhar on 19 February, though he was unhurt.

President Hamid Karzai's refusal to sign a bilateral security agreement for a continued American military presence after 2014 has made the international community – and many Afghans – anxious about the future. All three leading candidates have indicated privately that they would be willing to sign it, but only Dr Abdullah has announced his backing for it in public.

Mahmood Gailani, a former MP and head of Dr Abdullah's election campaign, said that the loss of vice-president Mohammad Qasim Fahim, who died last weekend from a long-running heart problem, could lead to more post-election instability if the ballot is not seen to be fair. Like Dr Abdullah, Marshal Fahim was from the Tajik ethnic group, unlike the majority of senior politicians who are Pashtun. Mr Gailani said the vice-president was a pacifying influence. "He was a bridge between the opposition and the president, he was always calming down both sides.Over the last five years as a vice-president there were many times that issues were solved by him. Whatever the situation, he will be missed. One thing is clear – that in a bad situation he will be missed more."

Speaking about what would happen if the election result was not seen to be fair this time, Mr Gailani said: "You may have a coup …. Circumstances may turn ugly. It won't remain the same. It may go in armed clashes because one side will feel the other has been helped."

Dr Abdullah is understood to already be angry at President Karzai's interference in his brother Qayum Karzai's campaign – after the president encouraged his older brother to stand down and back another candidate, Zalmai Rassoul. The Free and Fair Election Foundation of Afghanistan has reported 26 cases of violation of electoral law during the first month of campaigning, including threats, abuse of public resources and negative campaigning.

Analysts worry that without some foreign military presence, the country will once again become home to in-fighting among the Mujahideen, tribal militias that fought the Soviets and the Taliban but who also fought each other in a vicious civil war in the intervening years. Six of the 11 presidential candidacies have Mujahideen fighters on the ticket.

Michael Keating, Senior Consulting Fellow at Chatham House, and former UN Deputy Envoy to Afghanistan, believes continued investment in the country's troops will be necessary to prevent civil war. "If foreign financial support to the Afghan National Security Forces continues to flow, then they will remain functional," he said. "[But] there are parallels with the situation 25 years ago. Najibullah's army and government collapsed and the Mujahideen took over when Russian subsidies stopped in 1992, not when the Soviet army withdrew from Afghanistan three years earlier. Reconciliation efforts need to be stepped up once a new president is in place. Without a political settlement, the already massive human and economic cost of this conflict will increase."

Zahra Atayee, 25, lives in Bamyan, a peaceful mountainous province in the centre of the country, with her husband Mokhtar and their three children, Freba, five, Somaya, three and Najma, seven months. Like the majority in the province, she comes from the ethnic Hazara group, who still feel under-represented in government and were persecuted by the predominantly Pashtun Taliban.

During Taliban rule, her grandfather and uncle were murdered and she fled to Iran. For the last 10 years she has been back in Bamyan town. "I'm very concerned about the Nato troops leaving, especially for the Hazara people because they are weak and they will not be able to fight," she said.

Ms Atayee cannot read or write and believes peace is essential to the better future she wants for her children: "I hope my daughters will be educated and have more freedom. I hope they are not prevented from advancing by war."