The Center for Research on Globalization reported the initial airstrikes were followed about a half hour later by two more periods of explosions in the distance. Five or six dozen bombs were dropped, leaving smoke and odors that lingered in the air, witnesses told the independent research and media organization.
There also were signs of anti-aircraft activity, the report said.
It wasn't known how many casualties there may have been.
Libya has been mired in civil war that started in February with demonstrations seeking the ouster of strongman Moammar Gadhafi.