US missiles struck the former home of Taliban leader Mullah Mohammad Omar, it was revealed today.
The attack was came as America launched its first daylight raid on Afghanistan.
High-flying jets bombed the stronghold of the ruling Taliban militia in southern Kandahar.
Omar's house in Kabul was hit but he is still alive, Taliban officials said.
The Taliban claimed the US American planes "fled" from anti-aircraft fire during the attacks.
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 this morning said the victims were UN workers who cleared anti-personnel mines in Kabul, one of the world's most heavily mined cities.
Doctors at Kabul's Wazir Akbar Khan Hospital said a fifth man was treated and released.
Mohammed Afzl, who said his brother was killed, sat in front of the collapsed two storey building where the office was located, waiting for bulldozers to clear the rubble.
The United States has emphasised that it is not targeting civilians in its military campaign. The mine-clearing office was located in a building near a Taliban radio tower.
Targets in last night's raids included areas around the capital, the Taliban's home base of Kandahar and Afghanistan's north, where opposition groups are battling the Taliban, which controls nearly all of Afghanistan.
The independent Afghan Islamic Press agency in Islamabad, Pakistan, said targets included the airport in Kabul and a hill where a TV transmission tower is located.
The agency said one bomb landed near a 400 bed women's hospital in Kabul but made no mention of any damage. The reports could not be immediately confirmed.
General Richard Myers, chairman of the Joint Chiefs of Staff, said the fresh bombardment last night was accompanied by a renewed air drop of food aid.
In Kabul, farmer Adam Khan and his family of five fled today on a truck piled high with belongings, heading out of the capital to an eastern district to escape more air strikes.
They had been sleeping in their basement during the latest US bombardment, he said.
"All night the women and children were crying," he said. "They were very worried - scared."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article