US-led coalition forces "inadvertently" killed four women and a child during a clash with militants in a central Afghan province, the military said Friday. Meanwhile, a coalition service member died in a roadside blast in the nation's west. Civilian deaths are a sore point between the Afghan government and foreign troops here. Afghan President Hamid Karzai has pleaded with the US and NATO to avoid killing innocents and undermining already tenuous popular support for his government. Military officials have pointed out that insurgents often hide in civilian-heavy areas. Several militants also were killed and three detained in the clash Thursday in Ghazni province's Giro district, a coalition statement said. Coalition forces were aiming for a Taliban militant suspected of aiding foreign insurgents. As they approached a compound, several armed militants threatened them. The troops used small-arms fire in response, killing the militants as well as four women and child with them, the statement said. "The coalition regrets the death of these noncombatants," said Lt. Col. Rumi Nielson-Green, a coalition spokeswoman said. "We are planning to conduct a full and thorough investigation." Afghanistan is facing a raging Taliban-led insurgency that is strongest in its south and east. More than 2,900 people have died in insurgency-related violence so far this year, according to an Associated Press tally of figures from Afghan and Western officials. The last three months have been particularly deadly for American forces, pushing the US death toll to at least 500 since the invasion that drove the Taliban from power in 2001. In all, at least 600 Afghan civilians were killed from January through July, a 30 percent increase from the same period last year, according to the AP tally. The coalition did not specify the name or nationality of the service member who was killed Friday morning, but said the death occurred in the western part of the country when a convoy struck a roadside bomb. In other violence, Afghan and coalition forces killed at least four militants in Nahr Surkh district of Helmand province in the south on Thursday. The clash occurred during a reconnaissance patrol, when the troops saw four militants laying a bomb near a road and engaged them, the coalition said.