JACKSONVILLE, Fla. -

Jacksonville police said someone in the Arlington area is using water bottles to make homemade bombs. Police told Channel 4 there have been at least two incidents where neighbors have heard explosions and later found plastic bottles in their lawns.

The first incident happened off Shallow Brook court Friday. The second happened Sunday about 6 miles from Shallow Brook off Atlantic Boulevard. Police said the explosions involve water bottles, but it's still not clear what is inside the bottles that is making them explode.

Ken Arnold showed Channel 4 security video from his home that shows a water bottle foaming and a person checking it out, just yards away from his home. Arnold said around 5 p.m. Sunday at Mathews Crossing Apartments, he was walking his dog when he saw four young teens playing nearby.

"Two minutes later a water bottle landed a little ways from me and I said, 'Did you just throw that at me?' and they were laughing, and then I noticed that it was foaming," said Arnold. "One kid said, 'You might want to get away from it.' Well, I kicked it over there between these two trees and as soon as I did that, it exploded."

Arnold said he was shocked. He said the teens ran away laughing and he called police.

"I was wearing shorts, no socks. I could have easily had a flesh burn from the chemicals," said Arnold. "If it landed near my dog, it could have easily burned her eyes, her skin."

Rachel Fajardo lives across the street from Arnold and told Channel 4 that she is terrified.

"This really scares me. Maybe we should get a neighborhood watch," said Fajardo.

Police said homemade bombs went off just days before in the Shallow Brook subdivision. The victim in that case told police that he woke up to find two melted water bottles in his yard. A neighbor in that area told Channel 4 that he heard two loud explosions overnight.

"I heard about two loud bangs," said Michael Copeland. "Almost consistent with someone punching a tire and it exploding all at once."

Police said it is still not clear if the two incidents are connected.