Two Boys Accused of Planting Bombs : Arrests: Authorities link pair to four homemade ‘acid bombs’ that exploded Friday at two elementary schools.

Two 13-year-old boys have been arrested on suspicion of planting homemade bombs at two elementary schools here, and authorities said Tuesday that there have been a growing number of such incidents throughout South County.

The boys, whose names were not released because of their ages, were arrested Monday in connection with the planting of four “acid bombs” that exploded Friday--three at Del Cerro Elementary School and one at Glen Yermo Elementary School, Sheriff’s Lt. Robert Rivas said.

The youths, one a student at La Paz Intermediate School and the other a student at Los Alisos Intermediate School, were released to their parents that same day, and charges against them are pending in Juvenile Court, Sheriff’s Sgt. Robert White said.

According to Sgt. Charles Stumph, supervisor of the Sheriff’s Department Bomb Detail, no one has been hurt by the homemade bombs, which local youths are fashioning by putting readily available household acids and a reactive material in two-liter plastic bottles.

The chemical reaction between the acids and the other material produces a gas that causes the tightly capped bottle bombs to explode when the pressure reaches a sufficient level.

Several such bombs have exploded in recent weeks in mailboxes, cars, homes, schools and on playgrounds. Three of the devices exploded Tuesday at residences in Lake Forest and Mission Viejo, Stumph said.

The explosions can propel plastic fragments and acid droplets 50 feet in every direction and could cause severe burns, depending on the acid used.

“It’s very lucky that no one has been splashed by the acid from these bombs,” Stumph said.

Authorities first saw these homemade bottle bombs in Orange County nearly two years ago, but they were rare until the last several months, when there was an increase seen in South County, he said.

The ease of making these bombs might have made them popular with youths, officials said.

“We’ve got a problem with juveniles who are out for a thrill,” Stumph said.

On Friday, two of the bombs exploded near classrooms at Del Cerro about 1:50 p.m. and a third detonated within minutes on a sidewalk above the same elementary school, officials said. About three hours later, a fourth exploded on the playground at Glen Yermo.