KABUL, Afghanistan – Scattered violence ranging from airstrikes to roadside bombs killed at least 21 people over a 48-hour span, including U.S. troops, Afghan children and members of the Afghan security forces, officials said Saturday.

The Muslim holy month of Ramadan has failed to provide a respite from the deaths and injuries of civilians and soldiers across Afghanistan, although U.S. military fatalities are climbing at a slower rate this month than in July, the deadliest month of the war for American forces.

This year has seen a sharp increase in civilian casualties. The United Nations reported a 31 percent jump in noncombatant deaths and injuries in the first half of 2010, three-quarters of which were blamed on the Taliban and other insurgents.

The NATO force accepted responsibility, however, for some of the deaths Friday and Saturday.

Three Afghan policemen were killed in an apparently errant coalition airstrike in Jowzjan province, in Afghanistan’s north, NATO’s International Security Assistance Force said. In Farah province, in western Afghanistan, a woman and two children were killed in an airstrike that was aimed at insurgents, it said, and expressed regret over the civilian deaths.

Officials in Helmand province, in Afghanistan’s volatile south, said Saturday that six Afghan policemen had been found dead after insurgents overran their post the previous night. According to a provincial spokesman, Daoud Ahmadi, the attackers made off with a cache of weapons.

The south, the traditional stronghold of the Taliban, continues to account for the bulk of Western military casualties. A U.S. service member was killed Friday and two more Saturday in attacks in the south, military officials said without specifying the locations. A fourth, a Briton, was killed Saturday in Helmand province.

In Afghanistan’s north, which has become a much more active battle front in recent months, five civilians were killed by an improvised explosive device, military officials said Saturday. Buried bombs account for the majority of troop deaths, but also kill and maim hundreds of civilians every year.