Two runners died while participating in Sunday's Philadelphia Marathon, the race's director said.

Melanie Johnson, the executive director of the Philadelphia Marathon Race Weekend, said that race organizers "are deeply saddened" by the deaths.

The two runners' identities were not immediately disclosed, as officials were still working to notify their families. Johnson vowed that such information will be provided "as it becomes available."

"Our thoughts remain with the runners' families and friends," Johnson said.