Get the latest updates as we post them — right on your browser

. Last Updated: 07/27/2016

Mail, Pipe Bombs Rattle California

SAN DIEGO, California -- Security will be increased at government offices across California following the discovery of three mail bombs in as many days, and the eruption of two other devices in northern California last week.

Police arrested two men Sunday in the bombings of a courthouse and a bank in Vallejo, north of San Francisco, but no one has been apprehended for mailing pipe bombs to three addresses here, including the FBI office. Police and federal investigators do not believe the bombings and the mailings are connected.

The arrests Sunday of Francis Ernestberg, 40, and Oston Osotonu, 24, in the Vallejo bombings cap a week of explosive activity in California that has rattled nerves up and down the state. An arrest warrant has been issued for a third Vallejo suspect, Kevin Lee Robinson, 29.

The bombers in Vallejo, police said, were part of a plot to disrupt the criminal justice system there. The motives in the San Diego case are not yet known. There have been no injuries in either case.

In San Diego, all three devices were pipe bombs delivered by mail. The two bombs that exploded in Vallejo had been put in place.

On Thursday, a suspicious package was discovered at FBI offices in the San Diego suburb of Kearny Mesa during a routine screening of incoming mail. The building, filled with about 200 employees, was evacuated and the package was removed by robot and detonated by a bomb squad in the FBI parking lot.

The FBI said the bomb was inside a brown cardboard box. Handwritten in the upper left corner were the French words: "Je suis prest" or "Je suis preste," meaning "I am quick" or "I am ready." The package also had six 32-cent stamps that appeared to have been canceled.

The device consisted of "two pipe bombs in a package sent through the U.S. mail," Assistant FBI Director Thomas Pickard said in Washington. "We have no information on the sender yet. We could not read the postmark."

Another similar device, with the same French phrase, was discovered at the offices of Laidlaw Waste Systems in the San Diego suburb of Chula Vista on Friday.

And on Saturday, Chula Vista police said Dave McGruer, a 45-year-old federal employee, received a package containing two pipe bombs. Bomb squad members, interviewed by the San Diego Union, described the device as "fairly sophisticated" and similar to the ones sent to the FBI and the waste management company, though it did not contain any French phrases.

McGruer opened the package, realized it was a bomb, threw it on the bed and called 911, police said. The device did not explode.

"This guy is 0-for-3 so far," Chula Vista police Sergeant Tom Keblish said of the San Diego-area bomber. Among the three bombs, "the pipes are the same-brass or copper ... shiny," Keblish said.

In northern California, bombs exploded last month in Vallejo outside San Francisco, and threats were received.

On Jan. 25, two children found a backpack filled with 30 sticks of dynamite and three detonators outside a Vallejo public library. The device was not primed to explode. Later the same day, however, a dynamite bomb exploded beside automated teller machines at a bank. No one was injured. Early Thursday morning, a powerful explosion erupted at the courthouse, breaking 22 windows and gouging a small crater in the wall. A wire led from the exploded device outside the building to an alley, where police suspect the bomber set off the charge.