Suspected Taleban militants launched a series of attacks as Afghanistan's landmark vote was getting under way.
More than 1,000 people have been killed in fighting this year
There were overnight rocket and bomb attacks on several polling stations and a candidate's house, but they failed to disrupt the vote.
At least two policemen and three suspected militants died in a clash in Khost province. A French soldier died in a landmine blast in the south.
Near Kabul two rockets were fired at a UN compound soon after the vote began.
One rocket hit a building. The other failed to go off.
"There was a small fire, one local staff member was slightly injured," said UN spokesman Adrian Edwards.
Night of attacks
One French special forces soldier was killed and a second seriously wounded when their vehicle ran over a landmine in southern Afghanistan, the French Defence Ministry said.
A statement said the soldiers had been on patrol safeguarding the election as "part of France's contribution to the US-led operation Enduring Freedom".
French troops operate around the southern border town of Spin Boldak.
Hours earlier in Khost's Sabri district, rebels attacked a security post, police said.
At least one US soldier and a member of the Afghan National Army were also hurt in the gun battle.
In the southern province of Helmand, a suspected Taleban fighter was killed in an assault on a polling station late on Saturday.
"In the exchange of fire between police and the Taleban, one militant was killed but there was no casualty on the police side and no damage to the polling station," provincial governor Mullah Shir Mohammed told the AFP news agency.
In other violence:
- Candidate's house comes under bomb attack in Nangarhar province. Five people injured, but candidate unhurt.
- Three rockets fired at Jalalabad airport. No-one injured.
- Militants launch rocket attack on polling station in Andar district of Ghazni province. No casualties reported.
- Three rockets fired at polling station in Dargam district of Kunar province. No injuries reported.
The violence comes after Taleban promises not to target civilians.
The BBC's Bilal Sarwary in Kabul says the militants have been trying to create a climate of fear - but there has been no sign that voters have been deterred from casting their ballots.
More than 1,000 people have been killed in violence linked to militants in Afghanistan so far this year, most of them suspected insurgents.
Seven candidates and about 50 US soldiers have also died.