The US has launched its first daylight raid on Afghanistan.
High-flying jets bombed the stronghold of the ruling Taliban militia in southern Kandahar.
It is a sign the US command is confident that earlier Anglo-American attacks have diminished the Taliban's capability to defend itself from an aerial onslaught.
However, the Taliban claims the US American planes fled from anti-aircraft fire.
Earlier, during night raids, four Afghan United Nations workers were reported killed in a raid on Kabul.
The strike on Kandahar, the seat of the rigorously Islamic militia that rules Afghanistan, came shortly after a lone, unidentified jet screamed through the early dawn sky over the capital, Kabul, dropping a bomb north of the city near the airport.
The US-led military campaign, in which Britain is also taking part, is aimed at punishing the Taliban for harbouring Osama bin Laden, accused of plotting the terrorist attacks on New York and Washington that left more than 5,500 people dead or missing.
Last night, three US bombs were dropped on Kabul from a high-flying jet.
Officials at the scene say the victims were UN workers who cleared anti-personnel mines in Kabul, one of the world's most heavily mined cities.