Kabul, Afghanistan (CNN) -- Two suicide bombers struck a joint U.S.-Afghan military base in central Afghanistan early Saturday, killing 13 people, authorities said.
Among the dead were a child, two women and four policemen, said Shahidullah Shahid, a spokesman for the Wardak province governor.
The attack wounded 78 others.
One bomber attacked the base on foot, then another one detonated a truck, Shahid said.
No international coalition service members died in the attack in Wardak's Sayedabad district, according to Maj. Adam Wojack, a spokesman for NATO's International Security Assistance Force. However two coalition members were wounded, Shahid said.
The Taliban claimed responsibility for the attack.
Violence against Afghan civilians fell in the first half of the year, according to a recent United Nations report. But even though attacks were down compared with the first six months of 2011, violence is taking a "devastating toll on civilians," the report said.
In the first six months of this year, 1,145 Afghans were killed and 1,954, injured -- down from the 1,510 killed and 2,144 injured in the same period a year earlier.
The drop marked the first time in five years there has been a fall in violence against civilians, the report said.
About 80% of the attacks against civilians are by anti-government forces such as the Taliban, the report said.
Journalist Abdul Qadir Sediqi contributed to this report