Kenya's government has confirmed that two engineers kidnapped in Iraq, west of Baghdad, are from Kenya.
Civilian contractors are regularly targeted by insurgents
Moses Munyau and George Noballa were taken hostage after an ambush on Wednesday in which their 10 Iraqi companions were killed.
It is not known who is holding the men, who work for Egyptian-owned phone company Iraqna, or their demands.
In 2004 three Kenyan truck drivers held hostage for over a month were freed after a ransom was paid by their firm.
Kenya has no troops in Iraq but their nationals have taken jobs for private companies.
Dozens of foreign hostages are being held in Iraq, as well as hundreds of Iraqi citizens seized by insurgents and criminal gangs.
Kenya's foreign ministry says it is difficult to get reliable information.
"So far we do not know who is holding them," foreign ministry official Binsai Chepsongol told AFP news agency.
"They have not gone public with any demands so we don't know whom to appeal to for their release," he said.
The engineers had been on their way to the western suburb of Abu Ghraib to repair a transmitter station with seven Iraqi bodyguards and three drivers when they were attacked, officials said.
Eight engineers working for Iraqna - six Iraqis and two Egyptians - have been kidnapped in the past.
The company, owned by Orascom Telecom, has vowed to continue operating despite the security challenges.