Six NATO-led soldiers were killed in separate attacks in southern Afghanistan, while 15 Afghan civilians died in violence elsewhere in the country, officials said Friday.

Two soldiers affiliated with the NATO-led International Security Assistance Force (ISAF) were killed in a roadside bomb attack Friday in the south, where another foreign soldier also died in a Taliban attack, the military alliance said in a statement.

Three more NATO soldiers were killed in a roadside bomb attack in the same volatile southern region, ISAF said in a statement.

The military did not disclose the nationalities of the deceased. However, a US military spokesman confirmed that three of the soldiers, who died Thursday, were American forces.

The recent deaths took to 63 the number of US soldiers killed in July, the deadliest month since the 2001 ouster of the Taliban regime for the some 100,000 US troops involved in the Afghan mission.

In a separate incident, a woman and a child were killed and another child was injured Friday morning in the southern province of Kandahar when a bomb was remotely detonated by suspected insurgents, the interior ministry said in a statement.

The attack in Kandahar city targeted a parliamentary candidate who survived the blast, it said.

Taliban militants have stepped up their attacks against candidates for the September 18 parliamentary elections. The militants had previously killed two other civilians in Koh-e-Safi district Thursday as they ambushed a convoy of a parliamentary candidate.

'Insurgents continue to wage war against innocent civilians involved in the election process as they attempt to deny Afghans stability and security,' Colonel Rafael Torres, the director of an ISAF military operations centre, said in a statement Friday.

'The killings appear to be an attempt to target parliamentary candidates as well as members of their campaigning teams,' he said.

Meanwhile, at least six Afghan civilians were killed in a militant attack in the south-eastern province of Ghazni Thursday, ISAF said in a statement Friday.

Seven other civilians also died Thursday in separate roadside bombs in the provinces of Ghazni, Paktia and Kandahar, the statement said.

The number of foreign troops killed in Afghanistan has risen sharply in the past months. According to the independent internet tracking website icasualties.org, 408 foreign soldiers have died since the beginning of the year.

Human rights groups say 1,074 civilians also lost their lives.