NATO says eight United States soldiers have been killed in bomb attacks in southern Afghanistan. An Afghan civilian was also killed.
The BBC reports the deaths make October the deadliest month for American forces in the eight-year war in Afghanistan.
On Monday, 14 Americans killed in multiple air crashes. In total this month 55 US troops are reported to have died.
President Barack Obama is under pressure to reinforce the US military presence by 40,000 troops.
A second round of the presidential election is scheduled to be held on 7 November. The first round was held on 20 August.