A Carroll County resident working in Nigeria was kidnapped Friday and is being held for ransom, according to his family and police there.

William Gregory “Greg” Ock, 50, of Bowdon was working on a power plant job for the Japanese conglomerate Marubeni Corp. in the West African country, according to his brother Michael Ock, who contacted The Atlanta Journal-Constitution Friday.

Reuters news agency reported that during the kidnapping  in the Niger Delta region, gunmen killed the American’s driver. They were demanding a $310,300 ransom, the report said.

Michael Ock, who lives in Marietta, declined to comment when reached by the AJC Saturday.

“We have been advised to stay quiet about this thing in order to avoid any further complications for my brother,” he responded by email.

The U.S. State Department has seen wire reports of the kidnapping, but had no additional information to provide, a spokeswoman said Saturday.

In a travel warning this month, the State Department recommended U.S. citizens avoid all but essential travel to several states in the Niger Delta because of the risks of kidnapping, robbery and other armed attacks. There were five reported kidnappings of U.S. citizens in Nigeria last year, according to the State Department.