BBC Correspondent Clinton Rogers: Drivers urged to check lorries (2'24")

One lorry was bady damaged

The fire service was called after a driver spotted a small blaze under a truck as he reported for work at early in the morning at AE George and sons in Bruton near Wincanton.

By the time fire crews arrived another truck was ablaze.

The driver, with another colleague, then discovered the rest of the devices planted in the wheel arches of the rest of the firm's vehicles.

Bomb disposal experts were called in

The pair removed the crude, home-made bombs before they could go off.

A bomb disposal unit from Wiltshire was called in, and police cordoned off a one square mile area while they searched for more devices.

No one has claimed responsibility for the attack, but animal rights activists are suspected.

The company used to transport live animals abroad.

Police searched the surrounding area

A Somerset Fire brigade spokesman said the incident could have been much worse.

"Around 40 devices were found and they could have caused a lot of damage," he said.

"It is only because some of the drivers arrive for work at that time that the fires were not much more serious.

"Whoever planted these devices had no regard for the people who work their or the firefighters who have to deal with the situation."

An Avon and Somerset police spokesman said: "At this stage we do not know who is behind the attacks.