Boeing said Thursday it is examining fasteners on some undelivered 787 jets after discovering problems with their installation in the latest manufacturing shortcoming to face the company.

The aviation giant, which faces intensified scrutiny from regulators following recent incidents and manufacturing difficulties, said planes already in service can continue to be flown safely.

"Our 787 team is checking fasteners in the side-of-body area of some undelivered 787 Dreamliner airplanes to ensure they meet our engineering specifications," the company said.

Boeing said it discovered during a quality check that some fasteners were "torqued incorrectly."