Elections in Afghanistan are taking place against an underlying "climate of fear" among many voters and candidates, US-based Human Rights Watch has said.
Election officials disqualified 21 warlords this week
The group say that Sunday's elections have been undermined by insurgent attacks and intimidation by warlords.
They accuse the Taleban and other militias connected to Gulbuddin Hekmatyar of attacking candidates, election workers and other civilians.
Campaigning for the parliamentary and provincial elections ended on Thursday.
The report issued by Human Rights Watch was based on over 100 interviews with candidates, election officials, human rights workers and other observers.
In addition to attacks by militias, the report said that voters and candidates were also intimidated by ongoing human rights abuses and repression by warlords and local strongmen.
An environment of self-censorship seemed to exist in parts of the country, with some candidates afraid to challenge local commanders or warlords by name.
A quarter of seats in the elections are reserved for women
And many female candidates faced difficulties in travelling and speaking publicly, the report said.
On Monday Afghan election officials disqualified 21 candidates from the elections for having links with armed groups.
But many Afghans believe there are considerably more militia commanders on the ballot than have been barred, the BBC's Andrew North in Kabul says.
About 2,800 people are running for parliament and another 3,000 competing for 34 provincial assemblies.