Over two dozen civilians were killed or injured as a suicide attack hit the Afghan capital of Kabul on Saturday, eye witnesses said.
The bomb detonated near the city’s private Shinozada hospital.
Police cordoned off the area and did not allow people to get access to the site of the blast. The contractors were not named.
Conflicting information is common after such attacks.
Three civilian contractors for the worldwide military force, all Americans, were killed in the blast in Afghanistan’s capital, the Associated Press and CBS News reported.
They are saying that the suicide bomber rammed a vehicle packed with explosives into a vehicle convoy apparently transporting foreigners.
The blast struck as schools were letting out for the day in Macrorayan, a Soviet-built housing estate lined with shops, hospitals and schools.
The scene of the attack is also located close to the US embassy and global Security Assistance Force (ISAF) headquarters, which triggered an alarm immediately after the explosion.
But the Taliban, who often don’t claim attacks that have a high number of civilian causalities, have launched a series of attacks in Kabul in recent weeks following the announcement of the death of Taliban leader Mullah Mohammad Omar.
Security sources said the target was a group of foreign security contractors working for DynCorp global . The auto bomb caused extensive damage to nearby buildings and cars.
The Taliban denied carrying out the attack.