An unknown number of people died; at least one was reported to be an American.

An unknown number of people, by some evidence in the millions, have died as a result.

One person was killed and an unknown number of people were injured.

An unknown number were made as test subjects and given to employees.

An unknown number of people were arrested or taken to the hospital.

An unknown number of party members have not turned up after being kidnapped, he said.

Halfway through, she gets a call from an unknown number.

But for an unknown number of other people, the drugs are failing.

An unknown number were also caught off Chile between 1932-79.

I was but one man against an unknown number of the "enemy".