Afghan President Hamid Karzai says extremist fighters carried out coordinated attacks across Afghanistan due to a “failure” of intelligence services – especially by NATO, but also by his country.

Nearly 18 hours of fighting in the capital and parts of three provinces ended early Monday, when Afghan troops backed by NATO helicopters attacked a building in Kabul where the last militants were hiding. Witnesses said they watched rocket-propelled grenades crash into the building repeatedly before dawn.

Mr. Karzai said Afghan security forces' courage shows they are capable of defending their country. The top U.S. and NATO commander in the country, American General John Allen, agreed, praising the Afghans' quick and well-coordinated response to the attacks.

The Taliban said the action that began Sunday was part of a “spring offensive.” Senior Afghan security officials say the attacks were carried out by fighters from the Haqqani network, which has ties to both the Taliban and al-Qaida.

At a Cabinet meeting Monday President Karzai demanded a full investigation.

The president's office said four civilians and 11 Afghan security personnel were killed in the attacks. Authorities arrested one insurgent and killed 36 others during the fighting that began on Sunday.

In Kabul, militants attacked parliament, NATO headquarters and an area that includes the U.S., German and British embassies. They also staged assaults in three eastern provinces – Nangarhar, Logar and Paktia.

Western embassies said none of their staff members was hurt during the 18-hour ordeal.

Coalition spokesman Carsten Jacobson said insurgents fired at targets indiscriminately, not to “achieve a military success, but to achieve publicity.”

U.S. Secretary of State Hillary Clinton called the attacks “cowardly” in a call to the U.S. ambassador to Afghanistan, Ryan Crocker.

Violence has continued in Afghanistan as coalition forces have begun withdrawing from the country and transferring security duties to their Afghan counterparts.

The United States and Afghanistan are pushing toward completion of a long-term strategic agreement defining the U.S. presence in Afghanistan once all foreign combat troops leave the country by 2014.