Gunmen burst into a compound in northern Afghanistan, killing 11 Chinese road workers and wounding five, an embassy official in Kabul has said.
The raid occurred this morning near the city of Kunduz, until now deemed a secure area as Islamic guerrillas concentrate their attacks in Afghanistan's south and east.
It came early just two days after about 100 Chinese workers had arrived at the site.
A Chinese embassy official said those killed were working on a road project for a Chinese company; the project was being financed by the World Bank."
Security guards exchanged fire with about 20 assailants, according to Xinhua news agency.
The attack will deal a body blow to Afghanistan's efforts to rebuild a country shattered by decades of war and occupation. President Hamid Karzai, installed in power after US forces helped topple the Taliban in late 2001, is on a visit to the United States.
Remnants of the ousted militia and their militant allies including al-Qaeda have vowed to attack foreign and Afghan troops as well as aid organisations, and disrupt landmark elections due in September.
The rebels have been most active in their old strongholds in the south and east, but an attack in the northwest last week that killed three foreigners and two Afghans from the Medecins Sans Frontieres aid group, and the Kunduz raid, have raised concern that the insurgency is spreading.