HIGHLAND HEIGHTS, Ky. (AP) -- Engineers are checking for weaknesses in steel used to construct two Ohio River bridges on Interstate 275, some 5 miles east of Cincinnati.

Kentucky Transportation Cabinet spokesman Chuck Wolfe said the tests are under way to ensure the safety of the Combs-Hehl twin bridges where cracks were discovered in three steel plates. Wolfe said laboratory tests indicated steel used in the plates didn't meet the state's specifications for strength.

Wolfe said no other cracks have been found in the bridges. A team of engineers from the Kentucky and Ohio transportation agencies and the Federal Highway Administration recommended that the remaining steel in the bridges be tested. Contractors from Louisville have been hired to conduct those tests.

Wolfe said "we believe the bridges are safe or else they would be closed."