OSAKA - Flights in and out of Osaka Itami Airport in the western Japanese prefecture of Osaka were disrupted on Tuesday morning after cracks were found on the surface of one of the main runways, local press reported.

The cracks were found at around 6:20 am local time when members of the airport staff were patrolling the 3000-meter runway before the daily operation starts at 7:00 am, the report said. Following the discovery, the airport operator closed the runway in order to carry out repair work.

According to the report, the damage was spread with an area of about one square meter in the central part of the runway.

Due to the work, the runway was closed for about 40 minutes and a few domestic flights in and out of the airport were delayed, or forced to divert to Kansai International Airport in the morning hours.

The airport authority ordered investigation into the cause of the damage while pointing out that the cracks could be have been caused by this summer's high heat under the surface, which had become a problem as the runway aged.