There could be a more down-to-earth explanation behind the strange lights that appeared over Phoenix on Monday night, according to one Phoenix man.

Lino Mailo, 44, said he saw his neighbor launch several helium balloons with flares attached to them from the back porch of his north Phoenix home. Mailo said the balloons took off about 8 p.m., right before the mysterious lights were spotted.

�It's pretty tricky, because the higher the balloons get, the harder it is to tell what they are,� Mailo said.

A helicopter pilot with the Phoenix police department who was flying last night also saw the objects and said they appeared to simply be some flares hanging from helium balloons. Mailo said he has no idea why his neighbor released the balloons, but he regrets not filming the act.

�I feel bad for the people freaking out about this,� Mailo said. �I could've put this whole thing to rest.�

Civilian and military aviation organizations said Tuesday they had idea what caused the lights.

An official with the North American Aerospace Defense Command, which monitors the skies for security threats, said Tuesday the organization did not know where the lights came from.

Ian Gregor, a spokesman for the Federal Aviation Administration said that though air traffic controllers at Sky Harbor Airport witnessed the lights, they do not know the cause. Nothing appeared on radar and Gregor said the FAA will not be investigating.

�There's nothing to look into,� Gregor said.

Several Valley residents reported seeing the lights in the sky on Monday night and Gregor said the FAA received numerous calls. Witnesses said they saw four lights in a square shape that eventually became a triangular shape. The lights were moving to the east and they disappeared one by one.

Phoenix resident Kent Titze and his wife watched the lights from their house near Loop 101 and Cave Creek Road.

�It was something I've never seen before,� Titze said. �Right away I thought �UFO'.�

Titze's wife Fran rushed to take pictures of the lights.

�To me it looked like clusters of red lights - like three or five of them in each bundle,� Kent Titze said.

Republic reporters Claudia Koerner and Erin Kozak also contributed to this article.