Ambassador Ryan Crocker said Wednesday the attack that started Tuesday and ended Wednesday wasn't "a very big deal" for embassy personnel, calling it "a half a dozen RPG rounds from 800 meters away," The New York Times reported.
"If that's the best they can do, you know, I think it's actually a statement of their weakness," he said.
Afghan Interior Ministry spokesman Sediq Sediqi said eight people were killed in the assault -- four police officers and four civilians -- and 17 civilians were wounded.
Six coalition soldiers were also wounded, the International Security Assistance Force said on its Web site.
Afghan National Security Forces, supported by ISAF forces, ended the attack Wednesday morning, the coalition said. Afghan and coalition forces trapped the insurgents in the under-construction building they were using as their base and conducted a floor-by-floor clearing operation.
The Afghan Interior Ministry reported six insurgents died in the operation.
"In this attack, the insurgency succeeded in killing Afghan civilians, once again demonstrating their bankrupt ideology, which has been rejected by the Afghan people," ISAF Commander Gen. John R. Allen said. "Afghan security forces responded bravely, contained the insurgents, and systematically eliminated the threat. … The insurgency has again failed."
Crocker said similar attacks likely would be launched because insurgents have strong support in Pakistan, where the Haqqani network is based, the Times said.
"You can't keep every evildoer out of the city. You do have an insurgency that's going on in the country. It's particularly hard to do when you have safe havens," Crocker said. "And the information available to us is that these attackers … are part of the Haqqani network."
The insurgents used rocket-propelled grenades and small arms fire, targeting the U.S. Embassy, NATO headquarters, and government and foreign organizations.