The Pentagon Tuesday said it was trying to determine if a missile was launched Monday off the coast of Southern California and who might have launched it.
Spokesmen for the Navy, Air Force, Defense Department and North American Aerospace Defense Command said they were looking into a video posted on the CBS News website that appears to show a rocket or some other object shooting up into the sky and leaving a large contrail over the Pacific Ocean.
The video was shot by a KCBS helicopter, the station said Tuesday.
"Nobody within the Department of Defense that we've reached out to has been able to explain what this contrail is, where it came from," Col. David Lapan, a Pentagon spokesman, said. "So far, we've come up empty with any explanation."
Lapan said officials are talking to the Air Force, Navy and NORAD as well as civilian authorities who control and monitor air space.
"Right now, all indications are that there was not (Department of Defense) involvement in this," Lapan said, adding that some object might have been launched by a private company.
Officials had no information to make them suspect that the action was taken by any U.S. adversary.
"At this point, until we know more information about what it may have been, there is not alarm," Lapan said. "But that could change depending on what we find out."