Five cars parked outside the homes of workers from Huntingdon Life Sciences (HLS) were set alight within minutes of each other in the early hours.

Nobody was injured but the attacks drew a sharp reaction from police and staff at the Cambridgeshire laboratories, where experiments on rats, rabbits, dogs and cats are carried out.

The five cars were torched in four streets in Godmanchester. A sixth attempt in another street failed.

Police said it was lucky no-one was killed.

In previous attacks against workers at the company, which employs 1,200 people, four members of staff living in the village of Sawtry had their cars set alight in a midnight attack in May.

Two months before that, another worker's car was burnt out, while other employees say they have received hate mail.

An HLS said all the cars in today's attacks were owned by staff members, although not all were involved in animal experiments.

DCI Tom Hobbs of Cambridgeshire Police said: "This is the second spate of arsons on cars belonging to people connected with HLS. It is only by sheer luck that we are not beginning a murder investigation today."