More US mailbox bombs discovered

Authorities have urged people to be cautious

Six pipe bombs have been found in mailboxes in rural Nebraska in the United States, after six people were injured by similar devices in the states of Iowa and Illinois on Friday.

The crude bombs - none of which exploded - were discovered in the towns of Ohiowa, Columbus, Dannebrog, Davenport, Scotia and Seward. Officials said they had not been sent through the post, but placed there directly.

Four postal workers and two mailbox owners were injured in Friday's blasts. None of the injuries are life threatening, but one person remains in hospital.

Mailboxes are exploding! Why, you ask?... I'm obtaining your attention in the only way I can

Extract from note found with earlier bombs

Federal government officials described the bombings as "acts of domestic terrorism", and said notes had been found nearby warning of further "attention getters".

Special agent-in-charge from the FBI's Omaha office Wayne Dun said: "For the individual or individuals who may have been responsible for this: You have got our attention."

"We are not certain we understand your messages. We would like to hear from you - you do not need to send any more of these devices," he added.

Anti-government message

Gorlyn Nun, a 59-year old carpenter from Ohiowa made an unpleasant discovery when retrieving his mail on Saturday.

"I opened it up, my mail was there and there was a clear bag in there. I could see it was a pipe and it had a nine-volt battery in there," he told the Associated Press agency.

The first wave of bombs were left with messages criticising the federal government. The typewritten note began: "Mailboxes are exploding! Why, you ask?

Postal services have been suspended in some areas

"If the government controls what you want to do they control what you can do. I'm obtaining your attention in the only way I can... More 'attention getters' are on the way.

"If I could, I would change only one person, unfortunately the resources are not accessible. It seems killing a single famous person would get the same media attention as killing numerous un-famous humans."

It was signed "someone who cares."

Some postal deliveries in the affected states have been suspended. FBI officials have urged people to use caution when opening their post and report anything suspicious near a mailbox.

Home terror threat

In recent years the United States has been prone to bomb attacks carried out by its own citizens.

In 1998, Theodore Kaczynski, known as the Unabomber, was sentenced to four terms of life in prison without parole for a 17-year bombing spree which left three people dead and many injured.

The Unabomber waged his campaign for 17 years

Last June, Gulf War veteran Timothy McVeigh was executed for the 1995 bombing of a federal building in Oklahoma that killed 168 people and injured hundreds of others.

Following the 11 September attacks on the United States, the country was hit by a series of anthrax attacks, which the FBI believes was probably the work of a US national.