As the sun was setting off west Oahu, Hawaii’s third largest island, Tuesday spectators saw a mysterious zigzag light appear in the darkening sky.

Others on Maui and Lanai spotted the strange sight as well.

Image source: KGMB-TV

Image source: KGMB-TV

“Super bright … this long line … then it went into this loopty-loop,” Carie Matthews, an Oahu resident, told KGMB-TV.

“It was just a zigzag … almost looked like letting air out of a balloon,” Bryan Cuelho, also from the island, said. ”The first thing that came out of my mind was UFO.”

Other suggestions included a meteor or a flare.

Image source: KGMB-TV

Image source: KGMB-TV

The news station reported that police also received multiple reports of the strange light pattern, but neither they nor the U.S. Navy spokesman contacted by KGMB knew of any operations that would have caused the event.

“There was nothing unusual going on from our perspective at the time,” Maj. Julie Roberge with North American Aerospace Defense Command told KITV-TV.

Later KGMB reported that a local base was planning to launch a test missile this week, so the pattern could be related to that event. A resident told the news station she actually saw the missile go up around the time the pattern was spotted.

A few years ago, astronomer Jonathan McDowell, in explaining pattern in the sky thought to be the result of a missile but likely a jet contrail, said that at twilight the low sun can illuminate a contrail and make it “look vey dense and bright,” according to New Scientist.

Watch the KGMB’s report about the light with photos from some of its viewers and see what you think:

Check out more photos of the mysterious light submitted to KGMB on its slideshow.

(H/T: Gizmodo)