Kabul, Afghanistan (CNN) -- The Taliban militia said Tuesday the series of insurgent attacks in Afghanistan this week was well-planned and intended to show its enemies, including NATO, that it can strike secure locations.
Insurgents launched the wave of audacious attacks in Kabul and three other areas of the country Sunday. Government forces said they had repelled the coordinated offensives, but some of the violence in the streets of the capital spilled into Monday.
The Taliban said they launched fighters into battle with suicide vests, rocket-propelled grenades and hand grenades in Kabul and the provinces of Nangarhar, Paktia and Logar.
Zabiullah Mujahid, a Taliban spokesman, said targets were carefully chosen for assault by "our suicide-attacking friends."
For a time, insurgents occupied an empty building near the headquarters of NATO's International Security Assistance Force.
"We wanted to demonstrate our power to the enemy that even their safest and securest places can become under our attacks," Mujahid said. "And also we could target ISAF HQ from one of those positions and that was very important for us, because ISAF HQ is the most important military base of our enemy."
While the Taliban said they were behind the attacks, NATO members have indicated others were more instrumental.
U.S. Ambassador Ryan Crocker said Sunday, "The Taliban are very good at issuing statements, less good at fighting."
Crocker suggested the attacks may be the work of the Haqqani network, adding the Taliban did not have the capacity to carry them out.
Pentagon spokesman George Little said the attacks appeared to have the hallmarks of previous attacks by the Haqqani network.
One of the attackers arrested in Nangarhar on Sunday said during questioning that he was part of the Haqqani network.
Mujahid said fighters had been given maps and geographic details.
"Our mujahedeen brothers who launched Sunday's attacks were well-informed, educated and trained on how to carry out the task and how to do it properly. Important military trainings were definitely given to them," he said.
The nearly 18-hour series of assaults left four civilians and eight members of the Afghan security forces dead, Interior Minister Bismillah Mohammadi said Monday.
Thirty-five of the insurgents died in the violence, most of them killed by government forces, officials said.
ISAF said that as many as seven locations in Kabul were attacked, including the parliament building and the American, German and Russian embassies.
Gen. John Allen, the U.S. and NATO commander in Afghanistan, said the Afghans beat back the insurgents without allied assistance.
"They were on scene immediately, well-led and well-coordinated," Allen said. "They integrated their efforts, helped protect their fellow citizens and largely kept the insurgents contained." He said the attacks were meant to signal "that legitimate governance and Afghan sovereignty are in peril," but the Afghan response "is proof enough of that folly."
CNN's Mitra Mobasherat contributed to this report.