Hamid Karzai has been sworn in for a second elected term as Afghan president following an election mired in fraud, BBC reports.

In his inauguration speech, Mr Karzai addressed the key question of corruption, saying his ministers had be "competent and just".

Mr Karzai said that within five years he hoped Afghan security forces would take the lead and the role for foreign troops would be reduced.

He also invited his defeated rivals to join him in working for peace.

Kabul's streets were almost empty on Thursday as security forces set up numerous roadblocks ahead of the ceremony.

The international airport was closed, a holiday was called and people were advised to stay indoors as part of the security lockdown.

Dignitaries from about 40 countries were attending the ceremony, including US Secretary of State Hillary Clinton and Pakistani President Asif Ali Zardari.

In his speech, Mr Karzai addressed corruption, saying that good governance came from good management and that he would take care to ensure his ministers were "competent and just".

He said corruption was a "dangerous problem", adding: "We will soon organise a conference in Kabul to organise new and effective ways to combat this problem."

He added: "We have to learn from our mistakes and shortcomings of the last eight years."

Mr Karzai also invited his main defeated rival Abdullah Abdullah to work with him "for the prosperity of Afghanistan".

Mr Karzai called for a loya jirga - or grand assembly - to help bring peace. He said the strength of Afghan security forces had to be bolstered and the role of international forces reduced.

Mr Karzai also said he would step up the battle against the production and trafficking of drugs.