An investigation is continuing into two explosive devices that were found at an Oxford University college.
Templeton College is a graduate college in Egrove Park
The incendiary devices which were found at Templeton College in Kennington have been taken away for examination.
The site was cordoned off after staff raised concerns over claims, posted on a website by animal rights extremists, that the college had been targeted.
Police said officers who specialised in animal rights and domestic extremism were investigating the incident.
Forensic teams have examined four large liquid-filled plastic containers believed to contain petrol and bags full of pink material.
University security services found the devices after an "anonymous communique" was posted on an internet site that claimed there would be an arson attack - this was dated 18 February but was not posted until Saturday.
The posting was made by people claiming to be part of the Animal Liberation Front.
A spokeswoman for Oxford University said: "Obviously we have been very vigilant in recent months, especially after recent letter bombings.
"The university has its own security services who alerted the college when they discovered the posting on the website."
A Thames Valley Police spokeswoman told BBC News: "We still take these incidents very seriously, clearly an incendiary device is potentially very dangerous and this will be followed very fully by our team who've been working on animal rights for some time now and have good experience."
Templeton College, in Egrove Park, is a graduate college specialising in teaching and research.