KABUL, Afghanistan • Seven American soldiers were killed in fighting in eastern and southern Afghanistan over the weekend, after several weeks of declining death tolls among NATO forces.

In western Afghanistan, in Herat Province, police found the bullet-riddled bodies of five missing campaign workers for a female candidate in next month's parliamentary elections, and a body was found of another candidate for Parliament who had been shot to death, Afghan officials said Sunday.

The American servicemen were killed in five separate incidents, according to statements from the NATO-led International Security Assistance Force, known as ISAF. On Sunday, an American soldier was killed by an improvised explosive device in southern Afghanistan, while another died as a result of an insurgent attack in southern Afghanistan, the NATO force said.

On Saturday, insurgent attacks in eastern Afghanistan killed two American soldiers in one incident and one in a separate incident, while two other Americans were killed from an improvised explosive device in southern Afghanistan.

NATO officials did not release further details. The incidents brought the death toll for the month among coalition soldiers to 62, compared with 88 in July, according to icasualties.org, which tracks coalition fatalities. In June, the bloodiest month of the nine-year war, 102 NATO soldiers were killed, according to icasualties.org.

NATO forces have nearly tripled in Afghanistan since the beginning of 2009, with a total of 123,000 now. About 100,000 of them are Americans.

In the Herat Province incident, police said 10 campaign workers for Fawzia Gilani, a member of Parliament who is running for re-election, had been abducted last week. Five of them were discovered shot to death on Sunday, according to Col. Noor Khan Nikzad, a spokesman for the provincial police.

Elsewhere in Herat, Abdul Manan, a candidate for Parliament who was on his way to a local mosque, was shot to death by a gunman on a motorcycle, according to Nikzad.

In northern Baghlan Province, a NATO investigation gave credence to reports from local officials that eight civilians were killed during a night raid last week.

The ISAF said in a statement released on Sunday that a "full assessment" of the incident early last week in Talah wa Barfak District had determined that a helicopter that fired into the wrong building "may have resulted in civilian casualties."