Twenty ministers of the new Afghan Cabinet were sworn in Tuesday, the latest step in this war-wracked country's post-Taliban democratic revival.

Afghan President Hamid Karzai delivered the oath of office at the presidential palace in Kabul to each of the ministers, who placed their hands on a copy of the Islamic holy book, the Koran, and pledged to work for "the unity of Afghanistan."

The ceremony follows an April 20 vote by the country's 249-member parliament to approve most of Karzai's choices for key ministries. That ballot was the first by elected lawmakers to endorse a Cabinet following landmark parliamentary elections last year.

CountryWatch: Afghanistan

The result gave the U.S.-backed leader a boost as he tries to curb an intensified insurgency more than four years since the Taliban's ouster by U.S.-led forces for harboring Usama bin Laden and his Al Qaeda terrorist group that was blamed for the Sept. 11, 2001, attacks.

Five of Karzai's nominees, including the incumbent information and economy ministers and the sole woman, were rejected. The president must nominate new candidates for those ministries and a fresh vote held. No date has been set.

The key Foreign Ministry position went to Karzai's former foreign affairs adviser, Rangeen Dadfar Spanta, a former Kabul University professor who went into exile during the 1979-89 Soviet occupation of Afghanistan.

Spanta replaced the high-profile Abdullah Abdullah, the country's envoy since the 2001 U.S.-led invasion that toppled the Taliban regime.

Abdullah had close ties with Washington, but his ouster had been long anticipated because of an apparent falling out with Karzai over how the ministry was handling foreign affairs, observers said.

The three other key posts — defense, interior and finance — also went to Karzai nominees in a strong showing seen as an endorsement for the president's efforts to rebuild Afghanistan after almost three decades marred by Soviet occupation, civil war and Taliban rule.

Control over the security ministries is vital to Karzai as his government confronts a resurgent threat from Taliban extremists and other militants, who have stepped up bombings and other attacks in recent months across the country.