Kennewick police are investigating a rash of "Drano bomb" explosions that have blown up four mailboxes.

Drano bombs involve placing drain cleaner in a plastic bottle with some tinfoil. The chemical reaction of the hydrochloric acid and the tinfoil in the confined space causes an explosion, said Kennewick police.

Four incidents have happened -- all within a few blocks of each other:

At 8 a.m. Jan. 16, a resident at 2905 S. Garfield St. reported that his mailbox blew up but no one was hurt.

On Thursday, officers investigated a similar incident at 1102 S. Newport St.

At 5:30 p.m. Monday, the same type of explosion destroyed the replacement mailbox at 2905 S. Garfield St. At the same time, a resident at 1700 S. Olympia St. reported similar damage.

While no one seems to have been hurt, police worry about the potential hazard.

"We are asking parents to examine their cleaning supplies and determine if they have drain cleaner recently missing and in particular if they have teenagers in the house. We have reason to believe that the suspect(s) in these cases may live in the area of the crimes. It is important to put an end to this activity before there is a serious injury," Sgt. Ken Lattin said in a press release.