Kabul, Nov 19 (DPA) Afghan President Hamid Karzai was sworn in Thursday for a second term in office amid tight security at Kabul's presidential palace.

Security in the Afghan capital was tightened drastically out of fear of possible attacks by Taliban insurgents wishing to disrupt the inauguration.

Wearing a black lambskin hat and a green traditional striped silk coat over his shoulders, 53-year-old Karzai took his oath in a nationally televised ceremony attended by hundreds of tribal elders, Afghan ministers and foreign dignitaries.

'I swear to obey and safeguard the provisions of the sacred religion of Islam, to observe the constitution and other laws of Afghanistan and supervise their implementation,' Karzai said, repeating the oath of allegiance read to him by the country's chief justice, Abdul Salam Azimi.

Karzai then swore in his two vice presidents, Marshal Mohammad Qasim Fahim and Mohammad Karim Khalili, both powerful ex-warlords and members of the country's two largest ethnic minorities.

Pakistan's President Asif Ali Zardari, US Secretary of State Hillary Rodham Clinton, as well as the foreign ministers of Germany, France and Britain took part in the ceremony.

More than 500 people, among them 102 international guests and 398 Afghan dignitaries, were invited for the swearing-in of the increasingly controversial president.

Kabul was calm as it was on complete lockdown with major roads leading to the presidential palace closed to traffic and all commercial flights cancelled at the city's only international airport. Thursday was declared a public holiday in Kabul, where the citizens were also told to avoid unnecessary journeys on the city's boulevards

Karzai was named president in the country's fraud-marred polls after his main challenger, Abdullah Abdullah, pulled out of a runoff scheduled for Nov 7.

Karzai, a tribal elder from the Pashtun Popalzai tribe, began his career as a dominant political figure when he was selected as the head of the interim administration at a conference in Germany after the ouster of the Taliban regime in a US-led invasion in late 2001.

He was then elected by Afghan representatives in a loya jirga, or the country's traditional grand assembly, in 2003, as the head of the transitional government, which then helped him win with an absolute majority the first democratic presidential election in 2004.