Two incendiary devices have been found at an Oxford University college.
Templeton College is a graduate college in Egrove Park
Bomb disposal experts cordoned off an annex at Templeton College, Kennington, on Monday morning after concerns were raised by a member of staff.
The devices were found in a search which had been prompted by claims on an animal rights website that the college had been targeted.
Officers specialising in the activities of animal liberation groups were dealing with the incident.
A Thames Valley Police spokeswoman stressed this was one line of inquiry, and that she could not confirm the nature of the devices.
Bomb disposal experts were called in and the immediate area was evacuated as a precaution.
Police said there was not thought to be any immediate danger to members of the public.
The devices were found after an "anonymous communiqué" was posted on Saturday on a website which gives details of animal liberation groups' activities.
The posting claimed an arson attack had been carried out some days earlier on the college's offices.
It read: "This latest action is part of an on-going fight against the University of Oxford and its continued reign of terror over the unseen victims inside its animal labs."
A University spokeswoman said: "Obviously we have been very vigilant in recent months, on the look-out for activity of this kind and especially after the recent letter-bombings.
"The university has its own security services who alerted the college when they discovered the posting on the website.
Police would not confirm the nature of the devices
"We have increased security in recent times but obviously staff and students need access to university buildings and nobody would like us to make them into a fortress."
She said that those using Oxford University premises had all been made aware for the need for increased vigilance.
Iain Simpson from Pro Test - an Oxford-based group campaigning in favour of continued animal testing - told the BBC that the incident had failed to rattle his colleagues.
"These incidents are much less common than they were," he said.
"More and more scientists are coming out, speaking about the work they do, explaining how their use of mice and rats models does help to come up with some cures for some hideous diseases."
Located in Egrove Park, Templeton is a graduate college specialising in teaching and research on business management.