Gunmen have killed at least 12 Iraqi workers travelling home by bus from a factory in the western outskirts of the capital, Baghdad.
Bomb attacks and shootings are a part of daily life in Iraq
The attackers followed two buses as they left the government-owned company in the Abu Ghraib area, a security official was quoted as saying.
Hospital officials said 32 people had been injured in the attack.
Insurgents have been targeting Iraqis believed to be working for the US-backed government.
The latest attack targeted the employees of a firm owned by the ministry of industry and minerals, security official Barakat al-Khazraji was quoted by the Associated Press news agency as saying.
They were heading home to Baghdad's Shia neighbourhoods of Sadr City and Shula, said a police sergeant, Ahmed Ali said.
Police put the death toll at 12 but hospital sources said the final number could be as high as 17.