Police are investigating whether an animal rights group is behind vandalism attacks on two Oxfordshire companies.
There have been many protests against the Oxford animal lab
A website linked to the Animal Liberation Front (ALF) said the group had targeted two suppliers of Oxford University's new animal research lab.
The site said properties in Cassington and Kidlington were graffiti-ed, while van tyres were burst in Kidlington.
Police said they were aware the ALF had claimed responsibility, but would not confirm if the firms supplied the lab.
The website said the ALF would "stop businesses dealing with the uni".
Thames Valley Police said they were investigating two incidents of "minor criminal damage" in Kidlington and Cassington between Friday 30 November and Saturday 1 December.
They said they were keeping an open mind as to who had carried out the attacks.
An Oxford University spokesperson said: "It is totally unacceptable that companies engaged in entirely lawful activities are being attacked and threatened in this way.
"The university remains firmly committed to the completion of a new facility to re-house animals used in potentially life-saving research."
The university is building the biomedical research facility in South Parks Road to re-house its animals.
It said 98% of the creatures used in research would be rodents and fish.
Work on the new lab was halted between July 2004 and November 2005 following a sustained campaign from animal rights groups.
An injunction was granted to protect all those providing goods or services to the university from intimidation and harassment.
Anyone with information about the vandalism is being urged to contact police.