Kabul, Afghanistan ? The top U.N. official in Afghanistan called Sunday for a swift investigation into a U.S. airstrike that left nine Afghan children dead, saying that such attacks would increase Afghans’ feeling of insecurity and fear.

In a statement, the U.S. military said Sunday that it regretted the deaths and was conducting its own investigation into the bombing Saturday that targeted someone a U.S. Army spokesman called a known terrorist.

Ground forces who checked the scene of the airstrike later discovered the bodies of nine children near the dead terrorism suspect, the military said. But Afghans contended that the Taliban militant targeted by U.S. forces had escaped.

“This incident, which follows similar incidents, adds to the sense of insecurity and fear in the country,” Lakdhar Brahimi, the U.N. special representative to Afghanistan, said.

The children were playing in the walled compound of their home early Saturday morning when an A-10 Warthog aircraft bombed the rural village of Hutala, in the province of Ghazni, 80 miles southeast of the Afghan capital.

U.S. Ambassador Zalmay Khalilzad said the intended target, former local Taliban commander Mullah Wazir, was killed in the attack, a claim Afghan officials and residents disputed.

A U.S. military spokesman at Bagram Air Base, north of Kabul, said Wazir’s body had been found near the site of the attack. He is believed to be responsible for the recent slaying of two foreign workers building the Kandahar-to-Kabul highway.

However, a spokesman for the governor of Ghazni said the airstrike missed the mullah.

“The Americans wanted to bomb Mullah Wazir, but they bombed a different house,” Jawaid Khan said.