The report is based on dozens of interviews with civilian victims of attacks and their families and a lengthy review of available documents and records.
Joanne Mariner, HRW's terrorism and counter-terrorism director, said in a statement: "Suicide bombings and other insurgent attacks have risen dramatically since 2005, with almost 700 civilians dying last year at the hands of the Taliban and other insurgent groups.
"Having security is of no use unless a massive amount of aid is invested into the community"
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"The insurgents are increasingly committing war crimes, often by directly targeting civilians. Even when they're aiming at military targets, insurgent attacks are often so indiscriminate that Afghan civilians end up as the main victims."
James Bays, Al Jazeera's correspondent in Afghanistan, said: "This report is full of legal details talking about the Geneva Conventions and the rules of war... The Taliban are a grass-roots organisation - many of their individual fighters are illiterates and so are the people who carry out the suicide-bomb attacks. They probably have never even heard about Geneva Convention, let alone read them.
"The other thing that the Taliban say is that they are fighting a massive military machine led by America ... and because of that, they have to use every tool at their disposal. They say suicide bombs is one of their tools, and that's why they pursue this tactic."
Ten-year-old Sharzad knows exactly what happens when a suicide attacker detonates his bomb.
One year ago, she was one of the victims.
|Sharzad, 10, suffered permanent injuries|
from a suicide blast that will affect her health
Today, sitting with her brother and sister, she looks like a healthy girl - but then she shows me the injuries.
They will affect her health for the rest of her life.
Sharzad's stomach was ripped open and she lost a large part of her intenstines.
She said: "I was saying the martyr's prayer - my brother stopped me. He said you are not going to die. My stomach was wide open ... I am a half-human now."
Nato also says several hundred civilians have already died this year. Last year, more than 4,000 people died in fighting.
Afghan officials say about a quarter of them were civilians.
But HRW says while about 900 were killed by foreign, Afghan and anti-government forces, another 300 to 400 deaths could not be positively attributed to either side.
In the report released on Monday, HRW cited figures showing an increase in suicide bombings in 2006 from 21 to almost 140, saying the overwhelming number of victims were civilians although the targets were mainly military.
"Suicide attacks killed eight times as many civilians as combatants," it said.
Plea to Taliban
HRW urged the Taliban, Hezb-e Islami and associated groups to cease all intentional attacks on civilians and civilian targets, and avoid all attacks which do not distinguish between civilians and combatants or which cause disproportionate harm to civilians.
HRW also urged Pakistan, the Taliban's former backers, to do more to secure the border.
The Taliban, drug-runners and criminals easily slip across the porous and rugged frontier.
Afghanistan and its foreign allies say the Taliban, which draws its support from ethnic Pashtuns on both sides of the border, have been bolstered by the ability to shelter and train in Pakistan.