Associated Press

KABUL, Afghanistan (AP) -- A large bomb exploded in the Afghan capital on Tuesday as the international military coalition hands over responsibility for fighting the Taliban insurgency to the nascent national army and police they have been training.

Kabul deputy police chief Mohammad Daoud Amin said the blast was near the Afghan Independent Human Rights Commission in the Pul-e-Surkh area of the western part of the city.

A police officer named Asadullah said the target was the convoy of Mohammed Mohaqiq, the country's second vice president and leader of the Hazara ethnic minority. Asadullah, who like many Afghans uses just one name, said a police vehicle was destroyed in the blast. Information on casualties was not immediately available.

The Taliban insurgency has been pressing an intense campaign of violence in the run-up to Tuesday's security handover, attended by NATO chief Anders Fogh Rasmussen and Afghan President Hamid Karzai.

The transition is a major milestone of the 12-year-old war, with the coalition insisting Afghan security forces it has been training for years are now strong enough to take the lead in the fight against the Taliban.