Afghan officials say a policeman shot two foreign female journalists Friday, killing one and wounding the other.
Authorities say the policeman has been arrested. The motive for the attack is not known.
The incident on the eve of the country's presidential election took place inside a police compound in the eastern province of Khost, near Afghanistan's border with Pakistan.
The Taliban has vowed to use violence to disrupt Saturday's national and local elections.
Last month, a prominent Afghan journalist with the French News Agency was killed by Taliban gunmen.
On Thursday, Jan Kubis, the United Nations Special Representative for Afghanistan, urged Afghan citizens not to let anyone deprive them of their right to vote.
Kubis said there might be difficulties and security problems, but Afghanistan is much better prepared for Saturday's election than it was in 2009.
The Taliban has claimed responsibility for election-related violence, including Tuesday's suicide bombing outside the Afghan Interior Ministry, killing at least six police officers.