Two students are still ill in hospital after a drug scare at a university.
Five students, reportedly first-year undergraduates at Lancaster University, were rushed to hospital after taking the cannabis-like drug Spice, a legal high sold in shops until it was outlawed in 2009.
The two people still in hospital have been reported as serious or critical, but police or the university have not given further details. The three others have been discharged.
Ambulances and police were called to the Grizedale College halls of residence at around 6.40pm last night, according to the university's online student paper, Scan.
In a warning to students, the university tweeted: "Urgent message: Several students have been hospitalised today after taking legal high Spice - please check on friends and call 999 if needed."
Vicky Tyrrell, a spokeswoman for the university, told reporters that police called university authorities to tell them the students had been taken to the Royal Lancaster Hospital.
According to Scan the university also sent students an email, reading: "Five students are in hospital, 2 of them critically ill following a suspected overdose of a drug called Spice.
"It is extremely important if you have taken the drug to call 999 immediately and call for an ambulance. Please also check on anyone you think may have taken it.
"Spice is a cannabis-based drug and can be bought over the internet. Packages may be labelled 'not for human consumption'."
Spice is a drug that mimics the effects of cannabis, but can also reportedly have stronger effects due to the chemicals used to make it.
It is classified as a synthetic cannabinoid which contains the same active chemical tetrahydrocannabinol (THC), which can lead to paranoia or a change in mood.
DrugScope, a charity and independent centre of expertise on drug use, said Spice is a collection of herbs or plant material which has been sprayed with synthetic cannabinoids, producing a cannabis-like effect when smoked, giving a feeling of relaxation or euphoria.
Side effects include a raised pulse rate, dry mouth, lowering of inhibitions, dizziness, agitation and paranoia.
Before its classification under the Misuse of Drugs Act, Spice was being sold in "head shops" where legal highs can be purchased.
Although now banned, Spice and similar drugs can still be bought on the internet, with China and the Far East the main areas for production.
DrugScope says there are no figures for the extent of the use of Spice but the number of sites selling the drug before the ban suggests a "substantial user base in the UK" and elsewhere.
Some drugs like Spice can be anything up to 10 times stronger than cannabis plants with users having "no idea" of the potency of the drug they are buying.
A statement released by Lancaster University said: "Shortly after 6.30pm yesterday evening, police were called to campus following reports that five students had been admitted into Royal Lancaster Infirmary after taking an unknown substance.
"The university issued a warning to students. Due to the serious conditions of the students and the fact the substance could not be confirmed as legal, officers attended the university to carry out a search of the students' rooms.
"Two of the students remain in hospital, and three students have since been discharged.
"Inquiries are ongoing to identify the exact nature of the substance."